Lockheed's Hellfire missile systems are used on US helicopters in Iraq

Earnings in the three months to June surged to $461m (�264.7m) from $296m a year earlier.

Sales rose 6% to $9.3bn in the period, buoyed by fast growth at its electronic systems unit, which covers short-range missile systems used by the US in Iraq.

A one-off gain of $27m from Lockheed's investment in satellite operator Inmarsat also lifted profits.

Inmarsat made its debut on the London stock market last month after offering its shares at �2.45 - valuing the firm at �1.1bn.

Its shares have since risen, and closed at 326.5 pence on Tuesday.

"The one area that is performing the best, that is really driving the growth in the quarter and the outlook in the future, is our systems and IT group," chief financial officer Christopher Kubasik told Reuters.

Jet sales slip

However, despite the rise in sales and profits, the group did say that its core aeronautic unit had not fared as well.

While profits from the unit inched up to $245m from $239m last time, revenues sank 8% to $2.9bn.

Lockheed said the slowdown was a result of a drop in sales of its F-16 jets, which are currently being phased out.

However, Mr Kubasik added that the group's newest planes - the F/A-22 and F-35 joint strike fighters - are not being produced in large enough quantities to make up for falling F-14 sales.

The problem has also been exacerbated by the US Defense Department's decision to cut costs by slashing the number of F/A-22s it had originally ordered.