Six years ago, a state-owned Chinese oil company called Cnooc Ltd. was making its first step into the rough-and-tumble world of Wall Street finance, attempting an initial public offering in New York and Hong Kong.

The result was utter failure. Poor timing, questionable advice from bankers, and a lack of interest by investors forced Cnooc to withdraw the offering at the last minute and wait more than a year before trying again.

"It was a learning process," says Cnooc Chairman and Chief Executive Officer Fu Chengyu, who was the company's vice president at the time. "We were a good company, but nobody understood us," he said. "We were determined" never to make the same mistake again.

Six years later, Cnooc is trying to make itself understood again -- and the world is paying attention this time. The state-owned offshore oil and natural-gas producer is pursuing the biggest overseas acquisition in Chinese history: An $18.5 billion competitive bid against Chevron Corp. for control of California-based Unocal Corp. The bid, and the preparations that led to it, illustrate just how far Cnooc has come in schooling itself in the arts of Wall Street corporate finance and in the sensitive politics of Sino-U.S. relations.

The company, 70 percent-owned by the Chinese government, has mobilized three investment banks, three law firms, a pair of media strategy groups, and a Texas lobbying firm with connections in the White House to help shepherd the bid toward success. Using tactics reminiscent of a U.S. political campaign, Cnooc's advisers have set up "war rooms" in Washington and Beijing to cope with the political furor whipped up by the bid and to win the backing of Unocal shareholders. And Mr. Fu himself is considering a visit to Washington to meet members of Congress and to present a human face for a Chinese company whose name most Americans are still wondering how to pronounce.

Driving Cnooc's strategy are a group of Chinese men who grew up amid the turmoil of the Cultural Revolution of the 1960s and 1970s, spent time studying abroad, and are now leading the takeover attempt or helping advise it. The men represent the vanguard of what many observers expect will be a stream of Chinese mergers and acquisitions that, taken together, may eventually dwarf the wave of Japanese overseas investment in the late 1980s and early 1990s.

Cnooc's strategy -- a hybrid of U.S. public-relations savvy and strong financial support from its state-owned parent company and state banks -- could form a template for other Chinese companies to follow.

"If Cnooc's bid goes smoothly, it could open up a torrent of further Chinese investment," says Christopher Stephens, an expert on mergers and acquisitions at the Coudert Brothers law firm in Hong Kong. "If it's held up, it could have a chilling effect on further Chinese investment" in the U.S.

Other Chinese companies are also assimilating U.S.-style corporate tactics into their expansion plans. When the $1.75 billion sale of International Business Machines Corp.'s personal-computer business to Lenovo Group of China sparked objections in Congress this spring, IBM turned to Brent Scowcroft, former national security adviser to Presidents Ford and George H.W. Bush, to help it clinch its deal. Home-appliances maker Qingdao Haier Ltd. has teamed up with two U.S. private-equity firms to try to outbid Ripplewood Holdings for America's washing-machine maker Maytag Corp. And earlier this year, Nasdaq-listed Chinese Internet company Shanda Interactive Entertainment Ltd. began accumulating shares in rival Sina Corp. in the first potential hostile transaction between two listed Chinese companies.

But the scale and sophistication of the Cnooc bid are unprecedented for a Chinese corporation.

In many ways, it made sense that Cnooc would be the first of China's three oil companies to take on such a challenge. While China's two larger oil and gas companies, PetroChina Co. and China Petroleum & Chemical Corp., have greater financial wherewithal, Cnooc is nimbler, more experienced in dealing with foreign companies, and, by all accounts, more Western in its management style.

While the bigger Chinese oil companies and their parents operated like traditional state enterprises, so sprawling that their assets included schools and hospitals, Cnooc has just 2,524 employees and has a series of exploration and production joint ventures off the coast of China with foreign oil companies, including Chevron. Half of its eight-member board consists of nonexecutive directors, all of whom are foreigners. Board meetings are conducted in English. When one of the independent directors, Kenneth Courtis, voiced reservations about a Unocal bid in March, Mr. Fu agreed to postpone the offer to give directors more time to study it.

"Even though this company is majority held by a (state-owned) parent, we run it no differently than Western companies," Mr. Fu said in an interview Sunday. Its motivations "are purely commercial."

The extensive planning Cnooc undertook for its Unocal bid -- investment bankers say the company started formulating its bid last September -- stems from the lessons it drew from a series of smaller transactions over the past several years, beginning with its failed initial public offering in October 1999.

Convinced that they had erred in leaving the fate of the deal in the hands of a single investment bank, Cnooc officials devised a rule to hire at least two banks for any future transactions. They also decided to take a far more active role in supervising the banks' work.

Armed with cash, Cnooc set out a strategy of building on its natural-gas assets. In 2002, Cnooc paid Spain's Repsol YPF SA $585 million for its Indonesian gas and oil fields, making it the largest offshore oil producer in Indonesia.

The company followed that transaction with additional deals in Indonesia and Australia. In the past four years, through acquisitions and expansion, Cnooc boosted daily production 57 percent to 382,513 barrels of oil equivalent. Its net proven reserves rose 20 percent to 2.2 billion barrels of oil equivalent. Profits rose 60 percent from 2000 to $1.96 billion last year on revenue of $4.46 billion.

But it was Mr. Fu's elevation to head of Cnooc in October 2003 that paved the way for the Unocal bid, according to people who know him. Much more than his predecessors, Mr. Fu was willing to take risks to make Cnooc bigger.

Whereas the previous Cnooc CEO preferred a low-key approach to acquisitions, such as buying minority stakes and engaging sellers in bilateral talks, rather than competitive bidding, Mr. Fu was attracted by the one-step leap in scale that a merger with Unocal would provide, the people who know him say.

Mr. Fu disputes that a similar deal wouldn't have happened under a different CEO than himself. "If either the prior management or this management had gone through" such detailed analysis and due diligence on Unocal, "I think the conclusion would be the same," he said.

Mr. Fu won't put a date on when he decided he wanted to go through with a bid for Unocal, but by last September, analysis and planning for such a bid was starting to kick into high gear, say people who have worked on the transaction. Numerous banks were pitching a potential transaction, and in February Cnooc formally hired J.P. Morgan Chase & Co. and Goldman Sachs Group Inc., Mr. Fu says.

In planning his move on Unocal, Mr. Fu turned to one banker in particular who was closer to the company than any other. Charles Li, a senior banker at J.P. Morgan charged with building the firm's relationship with Cnooc, worked at the company in the 1970s and had a decade of experience assisting it tap into the Western capital markets.

Like many of the top China bankers working for Wall Street firms, Mr. Li's biography traces China's own recent economic history. Born in Beijing in 1961, Mr. Li moved to northwestern China when his parents were sent to re-education camps. At 16, Mr. Li became a driller for the predecessor company of Cnooc. He spent a couple of years working on one of China's earliest offshore oil rigs, packed-- men to a tiny room far offshore. "They weren't really rigs," Mr. Li once said about them. "They were bloody shabby steel shafts" sticking out of the sea. But he learned English and developed a connection to the company that would pay off handsomely later on.

Plucking the name of the University of Alabama out of catalog at random, Mr. Li and his wife each won a scholarship and went off to earn a master's in journalism. Following a law degree at Columbia University, he was hired by Brown & Wood, which had a China practice and happened to do work with Merrill Lynch & Co., which later approached him in 1994 to be a banker.

At Merrill, Mr. Li worked on a secondary offering of national cellular carrier China Mobile, a landmark deal, and soon began courting Cnooc. He advised them on every deal they pursued starting with their successful IPO, and in 2002 Mr. Li helped Cnooc management take an early look at putting together a bid for Unocal.

The following year, J.P. Morgan wooed him from Merrill in part for his Cnooc relationship, a move that helped J.P. Morgan win a central role in the Cnooc bid.

Goldman Sachs made its pitch for the business late last year and has since leveraged off of its new head of Asian investment banking, Bill Wicker, an oil and gas banker based in Beijing who formerly worked for Texaco Inc. The deal will come as a boost to Goldman Sachs's new China investment banking joint-venture, which is headed by Mr. Wicker.

Recognizing the political and policy hurdles looming in Washington, Cnooc also began assembling a team of U.S.-based advisers to help navigate the process. Leading the lobbying on behalf of Cnooc is Akin Gump Strauss Hauer & Feld, the Dallas law firm with deep ties to both political parties. Cnooc tapped another Texas firm, Public Strategies Inc. of Austin, to handle communications. The company is being advised by another media-strategy firm, Brunswick Group, which specializes in mergers and acquisitions. The law firms Davis Polk & Wardwell as well as Herbert Smith of Hong Kong are also working for Cnooc. The oil company's independent directors are advised by the investment bank N.M. Rothschild & Sons and consulting firm CRA International Inc., as well as by the law firm Skadden, Arps, Meagher & Flom.

In Public Strategies, Cnooc is getting a firm with close ties to the Bush White House. One top executive, Mark McKinnon, ran President George W. Bush's media campaign in the 2004 election. Mr. McKinnon isn't working on Cnooc, however. The point person on the account is Mark Palmer, an expert in crisis communications. Before joining Public Strategies, Mr. Palmer ran communications for Enron Corp., the failed energy firm that became a symbol of corporate excess after its collapse in 2001.

Mr. Palmer suggests the challenge in the days ahead will be "getting people to see the business rationale for this proposed merger," that Unocal's large Asian reserves fit well with Cnooc. "This is about shareholder value and a business deal, not politics," he says.

By last Monday afternoon, two days before the bid was formally issued, officials with Public Strategies had set up shop at Akin Gump's offices on Dupont Circle in downtown Washington.

The challenges confronting the company are twofold: to introduce Cnooc to U.S. officials and to steer public debate on the pending deal toward the business motivation behind the transaction -- and away from the politics of U.S.-Sino economic relations. That's especially difficult in the current environment. Anti-China sentiment has been on the rise since the beginning of the year, fueled by unease over the record U.S. trade deficit and a widening sense among politicians in both parties that China is reaping the benefits of free trade without playing fully by the rules. The angst is reflected in the harder line toward Beijing being taken by the Bush administration. Officials have slapped import curbs on Chinese textiles, stepped up calls for protection of pirated U.s. intellectual property, and browbeaten China to end currency-management practices critics say give Chinese companies an unfair advantage in the world market.

But the strongest backlash is on Capitol Hill, where several initiatives are pending that threaten China with new trade sanctions. The harshest is a measure, headed toward a Senate vote in late July, that would levy a 27.5 percent tariff on Chinese imports if Beijing doesn't revalue the yuan.

"The environment is difficult," says attorney Daniel Spiegel of Akin Gump. "Washington looms large, as far as this transaction is concerned." A former diplomat, Mr. Spiegel now leads Akin Gump's international policy practice.

In addition to lobbying on behalf of Cnooc, Akin Gump will guide any final transaction with Unocal through an examination by the Committee on Foreign Investment in the U.S., or CFIUS, a high-level government panel that scrutinizes the national-security implications of mergers and sales. Also working on the deal from Akin Gump: former congressmen Vic Fazio, a California Democrat, and Bill Paxon, a New York Republican, along with Ado Machida, a former aide to Vice President Dick Cheney, and Barney Skladany, a Republican with close ties to conservatives in Congress.

Yet the timing of the bid only underscored the political dimensions of the looming fight; it was unveiled on the eve of a high-profile Senate Finance Committee hearing on U.S.-China economic relations, and as Congress is debating energy-policy legislation. And while hoping to keep debate focused on business, Cnooc isn't blind to politics. That's why the company pledged that all oil and gas produced in the U.S. will be consumed in the U.S and that most of Unocal's employees will keep their jobs, commitments intended to help "people can get beyond" the politics, Mr. Palmer says.

Moreover, Cnooc, already looking ahead to a review by CFIUS, is signaling a willingness to address U.S. security issues posed by the potential deal. "To the extent there's any concern, the company is willing to work within the CFIUS process," Mr. Palmer says.

All of those commitments, Messrs. Spiegel and Palmer say, are being fed into the public policy debate in Washington, as the lobbying and communication campaign begins to unfold. "Information is the most important ingredient in having people in Congress and the executive branch understand what this transaction is all about," Mr. Spiegel says. "That is the challenge."

Mr. Fu may make the case to U.S. regulators and even members of Congress in person. "I will go if it's needed," he said. "If I talk to them face to face, I believe they'll understand more about the company and about me."