Shake-Up at American Express Division : Finance: ‘About half a dozen’ managers who are believed to have hidden losses on Optima Cards are fired or have resigned.

American Express Co. said Thursday that it had fired or obtained the resignations of “about half a dozen” mid-level executives who it believes deliberately hid $24 million in losses on Optima Card accounts.

The financial services giant also named Frank Skillern, 55, head of its London subsidiary Acuma Ltd., as head of the troubled Optima Card operation, succeeding Anne Busquet, 41. It said Busquet will take another job with American Express but didn’t give specifics.

The personnel changes followed a nearly two-month investigation by the company’s outside law firm, Skadden Arps Slate Meagher & Flom, into underreporting of Optima Card losses.

American Express disclosed Oct. 2 that employees had failed to write off $24 million in bad debts, in violation of internal accounting policies.

People close to the company said the employees evidently hid some losses to make the relatively new Optima unit seem financially more successful than it was.

A spokesman declined to say how many employees had been asked to leave or to name them. But he said the investigation persuaded American Express that the violations were “deliberate.”

The spokesman said Skadden Arps found no evidence that American Express’ senior corporate management knew of the underreporting of losses.

The Securities and Exchange Commission and the Federal Deposit Insurance Corp. have been notified, he said.

Harvey Golub, American Express’ president, said in a letter to employees Thursday that “the few individuals who abused our systems clearly violated policies and our reputation for integrity.”

Golub earlier this week took control of American Express’ Travel Related Services subsidiary, which includes Optima and the flagship American Express charge card, travelers check and travel businesses.

TRS, long the company’s cash cow, reported an $88-million third-quarter loss, partly because of growing customer defaults on Optima Card bills.

The Optima Card, introduced in 1987, was American Express’ attempt to expand into the consumer revolving credit business dominated by MasterCard and Visa.

The episode marks the second time in recent years that employees of an American Express subsidiary were found to have deliberately misstated financial results.

American Express disclosed in 1989 that its Boston Co. money management unit had inflated profit figures by $30 million.

In his letter to employees, Golub said American Express will continue to offer the Optima Card but acknowledged that so far it has been a failure.

The cards, which extend lines of credit that can be paid off over time with interest, were issued only to holders of American Express charge cards, for which bills must be paid in full every month.

The company believed that its charge card holders were good credit risks.

“It seems clear now that some people act differently with charge and credit cards,” Golub said.