A large managed care company says it needs more time to determine how a review of a stock option program will affect its financial statements.

UnitedHealth Group Inc., Minnetonka, Minn., says it will put off filing its second-quarter Form 10-Q financial report with the U.S. Securities and Exchange Commission while it waits for an independent team to complete an analysis of the stock option program, which started in 1994.

UnitedHealth has faced questions about whether it accounted for the options program correctly and whether the rules for the stock option program gave some top company executives too much control over their own stock option compensation.

“During the 13-year period under review, the company made, in total, more than 45,000 separate option grants to roughly 15,000 individuals,” UnitedHealth says in a statement. “This review is ongoing and no conclusions have been reached.”

UnitedHealth will announce later if it must adjust historical financial statements or restate any previously filed financial statements, the company says.

UnitedHealth says it hopes its board will have preliminary findings from the independent review before the filing deadline for the third-quarter Form 10-Q.

Lenders that supply a $1.3 billion credit facility for UnitedHealth require the company to supply quarterly financial data. UnitedHealth has negotiated an agreement with the lenders that will give the company a 90-day extension on the usual second-quarter 10-Q delivery deadline, the company says.

“The company currently has no outstanding balance on this credit facility, which also supports its commercial paper program.

At the end of the quarter, UnitedHealth had $509 million in outstanding commercial paper and $750 million in available cash, the company says.

Standard & Poor’s Ratings Services, New York, says it has revised its outlook on UnitedHealth and the company’s operating units to negative, from stable, as a result of the uncertainty the stock-option accounting review is causing for prior-period earnings.

“The company and its accountants are still determining the appropriate accounting treatment for the stock-option plan, and an estimated range of outcomes is unknown,” says Shellie Stoddard, an S&P analyst. “The existence of this uncertainty is placing pressure on the company’s financial condition and the flexibility of its capital strategy.”

But S&P has affirmed the A counterparty credit rating on the parent company and the other ratings it has assigned to the company’s subsidiaries.

UnitedHealth still has extremely strong capacity to generate cash and profits, and “we still believe that accounting and tax impacts are unlikely to be large enough to impair our overall view of operating performance and balance sheet,” S&P says.