(Reuters) - Lockheed Martin Corp (LMT.N), the Pentagon's largest supplier, on Tuesday reported a 23 percent jump in operating profit and earnings per share in the first quarter, and raised its earnings outlook for the full year by 25 cents.

Lockheed, maker of the F-35 fighter jet, satellites and coastal warships, said revenues fell 4 percent compared to the first quarter of 2013, with only one of five business segments - aeronautics - reporting higher sales, as deficit-reducing measures began to take a toll on military spending.

Higher pension income of $86 million in the first quarter also helped boost earnings, a big swing from the $121 million pension expense seen a year earlier, the company said.

Lockheed reported net earnings of $933 million for the quarter, or earnings per share of $2.87, up from $761 million or $2.33 per share in the first quarter of 2013.

It forecast earnings per share of $10.50 to $10.80 for the full year, an increase of 25 cents from its guidance in January, and left unchanged its forecast of $41.5 billion to $43 billion in sales.