The U.S. Navy on Friday awarded a $2.4 billion contract to a unit of Los Angeles-based Northrop Grumman Corp. to design and build the first replacement amphibious assault ship.

Northrop Grumman Ship Systems in Pascagoula, Miss will build the first next-generation “bid-deck” amphibious ship, know as LHA 6. Northrop is expected to deliver the ship, which will support more than 20 joint strike fighters, by 2012.

Shares of Northrop shares rose 60 cents to $76.79 in after hours trading following the announcement, after shares rose 58 cents to $76.19 in regular trading Friday.