MBTA delays Green Line extension opening to 2021

The Massachusetts Bay Transportation Authority (MBTA) won't open the Green Line Extension until 2021, local news media reported late last week.

The date is four years later than the agency's most recent timeline, according to radio station WBUR Boston.

The announcement comes after the MBTA last year put the project on hold to find ways to cut costs. The agency also terminated contracts with several firms working on the extension.

In May 2016, the MBTA approved a scaled-down version of the project and brought the costs down from $3 billion to $2 billion.

Under the MBTA's latest timeline, service to the Union Square station in Boston would begin in June 2021, while service to the College Avenue station in Medford, Mass., would start in September 2021.

The 4.5-mile extension will feature one relocated station and six new ones.