Defense contractor Northrop Grumman ( NOC) posted a 47% surge in first-quarter profit, buoyed by sales of its electronic systems and progress in its shipbuilding sector.

The company beat analysts' expectations, earning $389 million, or $1.17 a share, up from $264 million, or 76 cents a share, during the same period last year. Revenue grew 8% to $8.32 billion.

Northrop raised its full-year profit forecast to a range of $4.65 to $4.90 a share, up from previous guidance of $4.50 to $4.75.

Rival Boeing ( BA) announced earlier today that its first-quarter profit plummeted 47%, chiefly due to pricing pressures and pending production cuts. Boeing said its results reflected the weakened commercial airplane market, a less favorable delivery mix in defense and higher expenses for research and development. As a result, the airplane maker lowered its 2009 profit outlook.

Northrop and Boeing are expected to compete for a politically charged $35 billion tanker contract in May. The new planes will replace the Air Force's 50-year old fleet of aerial refueling tankers. Defense Secretary Robert Gates anticipates picking a winner this summer.
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