WALTHAM, Mass. — Raytheon Co., parent of Tucson-based Raytheon Missile Systems, said Thursday that its second-quarter net income rose nearly 4 percent on higher demand for its weapons. The defense contractor also raised its outlook for the year.

Second-quarter sales at the Tucson missile unit rose 7 percent from last year, to $1.69 billion, while operating income increased 2 percent from second-quarter 2012.

The Waltham, Mass.-based parent company said it earned $488 million, or $1.50 per share, in the three months ending June 30. That’s up from $471, or $1.41 per share, in the same quarter a year ago.

After removing the effect of a tax credit and other items, the company said that it earned $1.64 per share. That’s above the $1.30 per share that analysts, on average, were expecting, according financial information company FactSet.

Revenue rose 2 percent to $6.1 billion from $6 billion. Analysts expected revenue of $5.7 billion, according to FactSet.

Raytheon Missile Systems saw its overall net sales rise primarily due to higher sales on its Standard Missile-3 missile-defense interceptor and international sales of Paveway guided-bomb kits.

During the quarter, Missile Systems booked $543 million in contracts for Advanced Medium-Range Air-to-Air Missiles (AMRAAM) for the U.S. Air Force, the U.S. Navy and international customers; $228 million for SM-3 for the Missile Defense Agency, $224 million for the Exoatmospheric Kill Vehicle, a non-explosive interceptor warhead, for the MDA; $132 million for Paveway kits for international customers; and $98 million for the Joint Stand-off Weapon guided glide bomb for the U.S. Navy and international customers.

Sales at Raytheon’s Integrated Defense Systems business unit rose 9 percent compared with second-quarter 2013, to $1.72 billion.

Among other operating units, net sales fell 2 percent at Raytheon’s Intelligence, Information and Services unit, while sales at its Space and Airborne Systems unit fell 5 percent, mainly due to lower sales on classified programs, the company said.

Parent Raytheon Co. said it expects its revenue for 2013 to be between $23.5 billion and $23.7 billion. That’s higher than its prior forecast of $23.2 billion to $23.7 billion. It expects adjusted earnings between $6 per share and $6.10 per share, up from an earlier forecast of $5.75 per share to $5.90 per share.

Analysts expect earnings of $5.44 per share and revenue of $23.5 billion for the year, according to FactSet.

Raytheon said that it ended the second quarter with a backlog of $32.4 billion, compared to $33.9 billion in the same period a year ago. Having a backlog can indicate future revenue for the company.

Assistant Business Editor David Wichner contributed to this report.