Updated from June 27

Shares of

Rambus

(RMBS) - Get Report

fell Wednesday after the company said it found discrepancies in past stock-option award dates, which could result in additional noncash charges for previous years.

The stock was recently off $2.45, or 10.6%, to $20.68.

The Los Altos, Calif., memory-chip company announced last month that it was launching an internal investigation into past stock-option grants, the latest in a slew of companies looking into alleged backdating of stock options.

On Tuesday, Rambus said its internal audit committee had reached a preliminary conclusion that the actual measurement dates for certain stock-option grants issued in prior years differ from the recorded grant dates for such awards.

As a result, Rambus said it may need to restate prior financial results, which could decrease its reported operating income and net income, or increase its reported losses. Revenue is not expected to be affected.

The company did not specify which years the discrepancies relate to. In its previous statement announcing the internal investigation, Rambus said the review would focus on options issued in or before 2003.

The company will only provide revenue results for its second quarter and revenue guidance for the third quarter when it releases it quarterly financial results on July 19.

Rambus said it would not be able to provide additional financial results for the second quarter until the audit committee has completed its investigation.