Quest Software said it would record $143 million in accounting adjustments related to stock option issues from 1999 through March 31, 2006.

The company also identified additional accounting errors in which software revenue recognition rules were inconsistently or incorrectly applied on software license and service transactions. Quest said it should have recorded intangible asset impairment charges when it discontinued some software products it had acquired instead of continuing to amortize them over the assets' remaining estimated useful life.

Quest found some other errors affecting the amount of net income and expenses recorded in prior periods. The company said most of the errors involved timing adjustments that eventually offset each other within the periods covered by the restatement or over the terms of the underlying customer contracts.

Quest said the total revenue of each annual period covered by the restatement would be adjusted by less than 1.2 percent of the amount previously reported. Total revenue is expected to decrease slightly in 2000, 2001, and 2005, and slightly increase in 2002, 2003 and 2004.