The financial crisis took its toll on the US defence sector on Thursday as Lockheed Martin slashed its 2009 earnings forecast for the second time in recent months and Northrop Grumman warned it would report a loss for 2008 due to a write-down of up to $3.4bn on goodwill on acquisitions.

Lockheed, the world’s largest defence contractor, cut its full-year earnings forecast to $7.05-$7.25 per share, down from the $7.65-$7.90 per share it projected in October and well below analysts’ expectations of about $7.85 per share. The change reflects the company’s need to make up shortfalls in its pension fund, which has been hit by the financial crisis. Lockheed said it was facing $470m in pension accounting adjustments, up from its October forecast of $60m.