Tutor Perini Corp. has been awarded a $133 million contract by Amtrak to construct a tunnel at the massive Hudson Yards project in New York, the company announced Monday.

The Sylmar firm will begin construction on the tunnel next month beneath the 26-acre Hudson Yards site, which is slated for 6 million square feet of commercial space, 5,000 residences, a public school and luxury hotel.

The 800-foot-long tunnel is designed to preserve an underground right-of-way for possible expansion of rail service under the Hudson River between New Jersey and Penn Station in New York City. It is being funded through a Federal Transit Authority Hurricane Sandy relief allocation.

Tutor already has a contract to construct the 1.7 million-square-foot South Tower of the Hudson Yards development, which has a total price tag of $4 billion. The value of the tower contract has not been disclosed.

Shares lost 26 cents, or 1.4 percent, to close at $18.19 on the New York Stock Exchange.