Northrop Grumman Corp. reported Thursday that first-quarter profit dropped but beat expectations. It warned that full-year profits will be lower than expected due to charges and delays associated with its amphibious assault ship.

Northrop reported net income of $264 million (76 cents per share), a 32 percent dip from $387 million ($1.10) in the same period a year earlier ahead of Wall Street’s expectations of 63 cents per share, according to Thomson Financial.

Sales for the Los Angeles-based defense and government contractor rose 5.6 percent to $7.72 billion also beating analysts’ forecasts of $7.7 billion.

Northrop was hurt by a pretax charge of $326 million (61 cents per share), related to problems with its LHD-8 amphibious assault ship program. Northrop had said that damage caused by Hurricane Katrina to its Pascagoula, Miss. shipyard displaced experienced workers and poor-quality wiring performed by replacement crews must be redone.

Northrop estimated its full-year profit will range between $4.90 and $5.15 per share, down from prior estimates. It stayed in line with previous estimates for sales, saying it expected $33 billion.

However, in the past two months, Northrop has landed a $40 billion deal to replace the Air Force’s aging aerial refueling tanker fleet and earlier this week landed a $3.7 billion deal to supply the Navy with its Global Hawk drones.

Shares in Northrop were up 3.2 percent to $71.73 in early trading Thursday.