Dell Inc. shares fell as much as 8 percent in extended trading Thursday after the computer maker revealed it found evidence of misconduct and errors in its accounting amid investigations by the U.S. Securities and Exchange Commission into the corporation's financial results.

The world's second-largest personal-computer maker will miss U.S. regulatory deadlines for filing an annual report. Officials are still trying to determine if Dell will need to restate financial results, the Round Rock, Texas-based company said.

Dell has said reviews indicate possible errors related to so-called accruals and reserves -- estimates of expenses or losses that have occurred but haven't been paid out yet.

"People will tend to assume the worst," said Mike Green, a fund manager at Benham & Green Capital Management in La Jolla, Calif., which owns Dell shares. "Let's get to the bottom of it and let's get there quick."

Shares of Dell, which is also is being investigated by the Justice Department, fell as much as 1.89 U.S. dollars to 21.50 dollars in extended trading. The stock rose 4 cents to 23.39 dollars at 4 p.m. New York time on the Nasdaq Stock Market and already had fallen 6.8 percent this year.

The PC maker, which has only reported preliminary results for the past two quarters, said it will miss the April 3 deadline for the annual report and the extended date of April 18.

The audit committee found a "number of accounting errors, evidence of misconduct, and deficiencies in the financial control environment," Dell said today in a statement. The committee is being led by Thomas Luce II, a former Dell director and lawyer who returned to the board in September.

The committee is still working with management and independent auditors to determine whether the errors require financial restatements for prior periods. The company had no further comment beyond the release, spokesman Bob Pearson said.

"You don't get a lot of detail from this release," said Chris Baggini at Gartmore Global Investments in West Conshohocken, Pennsylvania, which doesn't own Dell shares. "I can't imagine the reaction is going to be positive."

Dell also told executives and directors today they won't be able to buy or sell the company's shares until the company files its annual report for the year ended Feb. 2.

SEC spokesman John Heine said the agency had no comment.