HARRISBURG -- An executive of an Oklahoma oil and gas company was revealed Friday to be the largest source of a generous campaign donation made to state Attorney General-elect Tom Corbett through a national Republican fund-raising group in the waning days of his campaign.

Aubrey K. McClendon, the chief executive of Chesapeake Energy Corp., gave a total of $450,000 to the Republican State Leadership Committee, which in turn gave $720,000 to Corbett and Republican state groups in the final month of the election.

But the sources of all of that money did not come out until Friday, the deadline that state officials gave the Washington D.C.-based RSLC to comply with state law and reveal the sources.

A Wachovia Bank loan, a Wal-Mart Stores Inc. political action committee, and the College Republican National Committee supplied another $255,000 of the total sum the RSLC gave.

It's not clear how the group plans to repay the $145,000 in Wachovia loans. Timothy J. Barnes, the RSLC's executive director, did not respond to a telephone message Friday afternoon. McClendon also did not respond to telephone messages left at Chesapeake Energy offices in Oklahoma City.

Normally, political action committees are required to file reports regularly with the state, showing who donated money to the group and to which candidates the group gave money.

But in an Oct. 22 filing, the RSLC essentially listed itself as the source of a $480,000 donation on Oct. 15, raising an outcry from Corbett's Democratic opponent, Jim Eisenhower, and prompting state officials to order the RSLC to reveal the source of money given in Pennsylvania.

Eisenhower's campaign originally questioned whether the RSLC had used corporate money to fund the donation, which is illegal in Pennsylvania.

Many of the RSLC's donors listed in IRS filings are corporate sources, including Indianapolis-based Centaur Inc. and Harrah's of Memphis, both of which hope to open a slot-machine parlor in Pennsylvania, and slot-machine manufacturing giant International Game Technology of Reno, Nev.

While Barnes in October denied that corporate money was used -- individuals and partnerships legally may give money to candidates and political action committees in Pennsylvania -- he would not reveal the sources.

The RSLC later gave Corbett another $90,000 in cash and paid off a $25,000 campaign debt of Corbett's, while giving $100,000 to the state GOP and $25,000 to the House Republican Campaign Committee.

In the final two weeks of the campaign, Corbett did some of his heaviest spending, doling out $1.65 million, mostly for television commercials.

For the entire race, Corbett collected $3.79 million in cash and $697,000 in in-kind contributions, while spending $3.73 million, some of it in a bruising primary campaign.

His opponent, Jim Eisenhower, raised $2.17 million in cash and $23,000 in in-kind contributions and spent nearly $2.14 million on the entire race.

In unofficial returns, Corbett beat Eisenhower by about 120,000 votes, or 50 percent to 48 percent.