Northrop Grumman Corp. reported lower first-quarter profit than analysts expected and cut its earnings outlook for the year as manufacturing costs rose and the company stepped up investments in production of the B-21 bomber.

Northrop Grumman cut its annual profit forecast after it posted a 49% slump in first-quarter earnings on Tuesday, as it booked losses on its B-21 stealth bomber program due to higher costs, sending its shares down 12%.