A key figure in the world's largest banking scandal is participating in an attempt to take control of a major city of Houston aviation contractor, according to a lawsuit filed in federal court here.

National Commercial Bank-Jeddah, Saudi Arabia (NCB), which is controlled by the family of Sheik Khalid Bin Mahfouz, has claimed rights to 90 percent of the outstanding shares of Southwest Airport Services, according to documents accompanying the lawsuit filed by Sandra C. Bath , president of Southwest Airport Services.

Southwest Airport Services provides fuel and other services for general aviation aircraft at the city-owned Ellington Field. The company also provides fuel to NASA and transient military aircraft, and to Air Force One, the president's plane, when it comes to Houston.

Bath filed the lawsuit against the bank and her former husband, James R . Bath , a local entrepreneur.

"Mr. Mahfouz, as owner of National Commercial Bank, hopes to accommodate Mr. Bath 's desire to assume control of Southwest Airport Services Inc., and treat it as his personal piggy-bank as he has done over the preceding several years," says the lawsuit.

Mahfouz, formerly the chief operating officer of NCB, and associate Haroon Kahlon last year paid $225 million in a settlement with the Federal Reserve Board and the New York District Attorney's office for their and NCB's alleged roles in defrauding depositors and customers of the now-defunct, Luxembourg-based Bank of Credit and Commerce International.

As part of the settlement, charges that a New York state grand jury brought against Mahfouz in 1992 were dropped. Those charges alleged he misled regulators by pumping hundreds of millions of dollars into BCCI and secretly withdrawing funds.

Because of the alleged actions of Mahfouz and NCB, the U.S. Office of the Comptroller of the Currency ordered the liquidation of the bank's New York federal branch through a consent order. NCB is precluded from operating in the United States unless it reapplies with the Federal Reserve Board.

"The statements regarding the bank in the petition (lawsuit) are completely unfounded," said Houston attorney Antoinette van Heugten, who represents NCB, the largest bank in Saudi Arabia. "The bank has been extremely cooperative with both Baths to try to resolve the substantial balance owed the bank on a loan. And that's all this case is about."

The bank's claims to the shares stem from a $1.4 million loan in 1990 from NCB's federal branch in New York to Express Park Inc., a company that provided parking at Hobby Airport before going into bankruptcy.

James Bath is the guarantor on the defaulted loan. He pledged 900 of the 1,000 outstanding shares of Southwest Airport Services to the bank as collateral to secure the loan, according to court documents. Bath held the shares for himself and on behalf of his former wife as community property, the lawsuit says.

The pending Houston lawsuit, based in part on the OCC consent order that liquidated the NCB branch, challenges the authority of the bank to take control of the Southwest Airport Services shares.

Documents filed by NCB say the 1992 consent order does not prohibit it from enforcing loans or realizing collateral for loans. OCC officials declined to say whether the consent order prohibits NCB from acting on commitments made with the bank prior to the order.

Sandra Bath is asking U.S. District Judge Kenneth M. Hoyt to declare that the bank's claims to the shares of Southwest Airport Services are void.