Weatherford International Ltd, a Geneva based oilfield services and equipment company, announced that it will be restating its results back to 2007 and delay the 2010 annual report. The delay the company said is due to tax accounting errors stemming from failure of internal controls.

The errors relate to writing off tax assets that were booked on transactions between subsidiaries starting in 2007. The corrections amount to more than $500 million over 4 years starting 2007.

Other than the accounting issue the company will definitely get hit with lower revenue in the next year due to the ongoing turmoil in the Middle East and North Africa.