Apple Computer Inc. said Thursday an internal investigation has discovered irregularities in certain stock option grants made between 1997 and 2001, including one grant in question made to CEO Steve Jobs, which was later cancelled.

The company said the cancelled grant resulted in no financial gain to the CEO.

A special committee of Apple's outside directors has hired independent counsel to perform an investigation and the company has informed the Securities and Exchange Commission.

"Apple is a quality company, and we are proactively and transparently disclosing what we have discovered to the SEC," said Apple CEO Steve Jobs in a statement. "We are focused on resolving these issues as quickly as possible."

Shares of Apple closed earlier up $2.95, or more than 5 percent, at $58.97 on the Nasdaq. Shares were down $1.57, or nearly 3 percent, to $57.40 in aftermarket activity on the INET.