The US$9 billion (S$12.16 billion) acquisition of Sikorsky Aircraft from United Technologies Corp in November boosted sales in its mission systems and training (MST) business, which is also its second largest division.
Revenue from its aeronautics business increased 21 per cent, led by higher F-35 fighter jet sales. The business is Lockheed's biggest, accounting for 34 per cent of its total revenue.
The F-35 Joint Strike Fighter is the Pentagon's largest weapons programme and it is expected to spend US$391 billion to buy 2,443 of the supersonic, stealthy new warplanes.
The Pentagon's No. 1 weapons supplier now expects 2016 profit of US$11.50 to US$11.80 per share, up from its previous forecast of US$11.45 to US$11.75 per share.
The company's net sales rose to US$11.70 billion in the first quarter ended March 27 from US$10.11 billion a year earlier.
However, net income fell to US$794 million, or US$2.58 per share, from US$878 million, or US$2.74 per share, a year earlier.
Net income in the latest quarter included special charges of 21 cents per share related to job cuts.
Up to Monday's close, Lockheed's stock had risen 16 per cent in the past 12 months, compared with a 1.4 per cent decline in the S&P 500 index.