The proposed federal prison in Berlin, N.H., took a big step forward Wednesday.

The U.S. Bureau of Prisons has picked two Rochester, N.Y., companies to design and build the $230 million, medium-security prison, Sen. Judd Gregg announced.

“The jobs and economic benefits for the entire North Country region created by this federal facility will provide an important boost to the area,” said Gregg, who has shepherded the project through Washington.

A pleased Berlin Mayor Bob Danderson said the city looks forward to the construction jobs and, later, the 300 permanent jobs the prison will bring to the area.

The contract is going to Bell Constructors Inc. and Heery Construction Co., a joint venture.

The prison will have 1,280 beds and is expected to take three years to build.

Gregg, R-N.H., said it will be one of the largest public works projects in New Hampshire history.