UPDATE 3-Lockheed Martin beats profit estimates, raises 2018 forecast

(Updates shares)

July 24 (Reuters) - Demand for Lockheed Martin Corp's F-35 jet once again helped company profit beat Wall Street's expectations on Tuesday and the No. 1 U.S. defense contractor raised its forecast for the rest of the year.

But Lockheed shares reversed a nearly 3 percent rise at the open and traded flat as investors took profits from the defense company for the second quarter in a row.

Rising U.S. defense budgets and stronger foreign demand helped Lockheed raise its 2018 net sales forecast to a range of $51.60 billion to $53.10 billion from a range of $50.35 billion to $51.85 billion.

Full-year profit is now expected to be between $16.75 to $17.05 per share, compared with its earlier estimate of between $15.80 and $16.10 per share.

Revenue from the company's missiles and fire control business, which makes PAC-3 missiles, rose 16.9 percent to $2.09 billion. The PAC-3 is the interceptor in the Patriot missile system. In late March, Poland signed its largest arms procurement deal in its history, a Patriot missile defense system for $4.75 billion.

The company's aeronautics business, which makes the stealthy F-35 fighter jet, posted a 8.1 percent rise in revenue to $5.32 billion.

The company's net income rose to $1.16 billion, or $4.05 per share, in the second-quarter ended June 24 from $955 million, or $3.28 per share, a year earlier.

Net sales rose 6.6 percent to $13.40 billion.

Analysts were expecting adjusted earnings of $3.92 per shares and revenue of $12.74 billion, according to Thomson Reuters I/B/E/S.

The quarterly results included a charge of $96 million related to severance and restructuring activities, which reduced net income by $76 million, or $0.26 per share.

"Although Lockheed beating consensus for the quarter is hardly a novel experience, to do this despite the 26 cents of restructuring is an impressive performance," analyst Robert Stallard of Vertical Research said in a note on Tuesday.

Up to Monday's close, Lockheed's shares had risen 9.7 percent in the past 12 months, compared with a 13.6 percent rise in the S&P 500 index.

U.S. Senate and House negotiators on Monday reached agreement on a $716 billion defense policy bill. (Reporting by Mike Styone in Washington and Sanjana Shivdas in Bengaluru; Editing by Chizu Nomiyama and Bill Trott)