Computer Sciences Corporation (CSC) has delayed filing its annual report with the US Securities and Exchange Commission (SEC) because it has found "significant" accounting errors over multiple years, the IT services provider has announced.

The US-based company has uncovered mistakes in its accounting for tax liabilities in fiscal years 2000 through 2006, which is causing it to delay filing its 2007 10-K report, the company said.

Correcting these errors will result in a cumulative charge estimated to be between $300 and $400 million (£152 to £202m) through 31 March 2006. That charge is unrelated to a previously disclosed one of about $60 million related to a stock option investigation.

CSC will restate results for the periods affected by the accounting errors when it files its 10-K for the fiscal year ended 30 March 2007, which it expects to do on or before June 13 of this year.

Signs of possible accounting irregularities at CSC surfaced last week. Then the company was supposed to announce its 2007 fourth-quarter and year-end results. Instead, CSC said it was delaying reporting the results because it needed additional time "to finalise the accounting for income taxes related to certain prior-period transactions".

CSC is one of the world's largest IT services providers with about 77,000 employees and revenue of $14.6 billion in fiscal year 2006. The company is considered a particularly strong provider of IT services to government agencies.