By Ankit Ajmera

(Reuters) - Lockheed Martin Corp <LMT.N>, the Pentagon's No. 1 weapons supplier, reported better-than-expected quarterly revenue and lifted its 2016 revenue and profit forecasts for the second time, buoyed by increased deliveries of its F-35 fighter jets.

The company's shares — already up 18 percent this year — soared to a record high of $261.37 in early trading on Tuesday.

The results from the world's largest defense contractor is often seen as a bellwether for the U.S. defense sector. Northrop Grumman Corp <NOC.N> and Raytheon Co <RTN.N> are due to report quarterly results next week.

Lockheed is also benefiting from its $9 billion acquisition of Sikorsky Aircraft last year from United Technologies Corp <UTX.N>.

Lockheed raised its 2016 profit forecast to $12.15–$12.45 per share from $11.50-$11.80.

The company also said it now expected full-year sales of $50.0 billion-$51.5 billion, up from $49.6 billion-$51.1 billion it previously estimated.

Analysts on average were expecting a profit of $11.84 per share and revenue of $50.46 billion, according to Thomson Reuters I/B/E/S.

Lockheed said sales in its aeronautics business, the company's biggest, rose 6 percent in the three months ended June 26 as it delivered 14 F-35 jets, compared with 11 a year earlier.

The company has said it plans to deliver 53 F-35 jets in 2016, up from 45 a year earlier.

"(The) consensus expectations are finally positive for the F-35 and for improvement in the defense budget, which has led to a higher valuation," Bernstein analyst Douglas Harned wrote in a note.

The F-35 is the Pentagon's costliest arms program. The U.S. Defense Department expects to spend $379 billion to develop the plane and buy 2,457 of the supersonic, stealthy new warplanes, in the coming decades.

The company's net income rose to $1.02 billion, or $3.32 per share, from $929 million, or $2.94 per share, a year earlier.

Excluding income tax benefits of $11 million, Lockheed earned $3.28 per share.

Net sales rose to $12.91 billion from $11.64 billion.

Analysts on average had expected a profit of $2.93 per share and revenue $12.55 billion.

(Reporting by Ankit Ajmera in Bengaluru and Idrees Ali in Washington; Editing by Sriraj Kalluvila)