WASHINGTON -- The chief executives of Delta Air Lines and Northwest Airlines expect federal regulators to approve their proposed combination without requiring asset sales or other concessions.

Addressing the biggest industrywide concern these days, Delta Air Lines Inc. CEO Richard Anderson also said that, given current fuel prices, domestic carriers would need to raise fares by 15 percent to 20 percent just to break even. Anderson said higher fares would likely diminish demand for air travel, and prompt carriers to further reduce their schedules.

Oil prices rose today to an all-time highs above $118 a barrel. The cost of jet fuel in New York last Tuesday was $3.73 a gallon, compared with about $2.06 a year earlier.

Anderson and Northwest's CEO, Doug Steenland, told reporters they are confident the Justice Department will not require them to give up any gates or slots on the few routes where they do overlap because ample competition exists in those cities.

The carriers filed paperwork with antitrust regulators yesterday, Steenland said.

Steenland said any concerns about competition on international routes were answered earlier this month when the Transportation Department granted Northwest and Delta preliminary approval to share revenue and coordinate schedules across the Atlantic. The two carriers, along with Air France-KLM and two other airlines in the SkyTeam Alliance have sought immunity to essentially operate as one airline across the Atlantic. The Transportation Department's final ruling is due April 30.

Steenland and Anderson said they were in Washington to meet with lawmakers on the two committees holding hearings Thursday about their proposed combination, and with representatives from the states where they are based.

Delta's stock-swap deal to acquire Northwest Airlines Corp., if approved by regulators and shareholders, would create the world's biggest carrier. Investors have sent shares of both airlines down sharply since the deal was announced on April 14.

Shares of Atlanta-based Delta fell 40 cents, or 4.9 percent, to $7.80 in morning trading, while Eagan, Minn.-based Northwest dropped 47 cents, or 5.2 percent, to $8.59.