Lockheed Martin Corp on Tuesday reported a better-than-expected quarterly profit and raised its 2019 profit forecast for the second time in three months, helped by increased demand for its stealth F-35 combat jets and missiles.

The company's shares rose 2.1% before the opening bell.

The Pentagon's No.1 weapons supplier now expects full-year profit to range between $20.85 and $21.15 per share, compared with its previous forecast of $20.05 to $20.35 per share.

The company also raised sales estimate for the year to $58.25 billion to $59.75 billion, from $56.75 billion to $58.25 billion.

Lockheed's missiles and fire control unit, which makes missile defenses like the Terminal High Altitude Area Defense (THAAD), was one of its best-performing units where sales grew 15.6% to $2.41 billion during the quarter.

Sales from its aeronautics business, its biggest, rose 4.3% to $5.55 billion, powered by higher F-35 jets production.

The company delivered 29 of its stealth F-35 combat aircraft during the quarter, compared with 25 a year ago.

The Bethesda, Maryland-based company's net earnings rose to $1.42 billion, or $5 per share in the second quarter, surpassing analysts' expectation of $4.77 per share, according to IBES data from Refinitiv.

Sales grew 8% to $14.43 billion, above analysts' expectation of $14.21 billion.

(Reporting by Divya R and Rachit Vats in Bengaluru; Editing by Shounak Dasgupta and Maju Samuel) ((Rachit.Vats@thomsonreuters.com; within U.S. +1 646 223 8780, outside U.S. +91 80 6749 3798; Reuters Messaging: rachit.vats.thomsonreuters.com@reuters.net))