Federal banking officials are trying to arrange the reorganization of a fast-growing bank in Oklahoma City that has made millions of dollars in loans for oil and gas exploration at a time when sagging demand has caused drastic reductions in drilling activity, informed sources here and in Oklahoma said last night.

The sources said it is likely that the Penn Square Bank, Oklahoma's fourth largest, will be taken over by new management next week. The Federal Deposit Insurance Corp., which insures the bank's deposits, is reportedly seeking a transfer of ownership that would keep the bank operating and minimize the amount the FDIC would have to pay to depositors.

Oklahoma City television stations reported last night that customers, alarmed by new accounts of the bank's problems, were calling to inquire about the safety of their money and were lining up to withdraw funds at the bank's drive-in window, which was open during its usual Friday evening hours. The bank's main office was closed, but a moving truck was hauling furniture away.

Penn Square Chairman Bill P. Jennings, who has used the bank to provide capital to some of the most prominent figures in Oklahomas's energy industry, told reporters in Oklahoma City that the bank would open for business as usual today and that the depositors' funds were protected.

But sources in Washington said many Penn Square depositors have more than $100,000, the maximum covered by the FDIC, in the troubled bank.

Penn Square has 80 percent of its loans in energy ventures, according to American Banker magazine. The portfolio includes heavy investment in the troubled oil companies of one of its directors, Carl W. Swan, described by Oklahoma sources as a reclusive young wildcatter with close ties to Jennings.

The reported problems at Penn Square could cause ripples in banking circles far from Oklahoma, because the bank has sold more than $2 billion in loan participation to leading banks in New York, Chicago and Seattle.

These banks might be unable to collect if Penn Square folds because the security for the loans is "still in the ground," an Oklahoma banker said.

A spokesman for Seattle First National Bank, largest in the Pacific Northwest, confirmed yesterday that is has been notified by the U.S. controller of the currency that "certain Penn Square loans" have been "identified as problems. Penn Square lending is under review, including all participant loans."

About half the loan participations have been sold to Chicago's Continental Illinois Bank and Trust Co., which recently has been hit by a series of setbacks among borrowers it has backed heavily, including the bankrupt McLean Gardens condominium project here.

The other banks holding Penn Square loan participations are Chase Manhattan of New York and Northern Trust of Chicago.

A senior official of Penn Square, Bill G. Patterson, who was head of its oil and gas lending operations, was removed from his position earlier this week.

A year ago, Oklahoma's energy industry was riding high as drillers scrambled to find oil and gas in the Anadarko Basin, but reports from the state say many of the wells are coming up dry, leaving the borrowers unable to pay off loans for their drilling equipment and land leases.

Penn Square, which reported assets of $484.5 million at the end of December, wrote off about $4.2 million in loan losses last year.