July 2 (Reuters) - General Dynamics Electric Boat, the

submarine making unit of General Dynamics ( GD ), said on

Wednesday it received a $1.85 billion modification on its

previously awarded contract for Virginia-class submarines.

The modification is for long lead time material and

preliminary construction efforts for the nuclear powered

submarines, the company said.

The award, first posted on the Pentagon's website on June

26, is expected to be completed by September 2035, according to

the notice.

The announcement comes at a time when the submarines,

built for the U.S. Navy, is years behind schedule as a result of

labor shortages and supply chain issues.

"This contract modification allows for the acquisition

of critical material and components for Virginia-class

submarines that require substantial lead time to manufacture and

deliver," said Mark Rayha, president of General Dynamics

Electric Boat.