A key Southwest light-rail line contract increased by $21 million Wednesday due to numerous delays that have dogged the $2 billion project.

The Metropolitan Council, which is overseeing construction of the 14.5-mile line, extended an existing contract with Los Angeles-based AECOM for design and engineering services to Dec. 31, 2021. The amount of the agreement is now $140 million.

Project spokesman Trevor Roy said Southwest's overall price tag will not increase as a result of the council's action on Wednesday. It will fit within the project's capital budget, he said.

As of August, about $109 million of the AECOM contract had already been spent.

All told, about $500 million in local money has been spent so far on the Southwest project. The Federal Transit Administration is expected to pay for 46% of the project's cost. News on the federal grant is anticipated in the first quarter of 2020.

The light-rail project, which will link downtown Minneapolis with Eden Prairie, has been delayed several times because of budget cuts that required additional approval from the five cities the line serves, two rounds of bids for construction work, and lawsuits and negotiations with freight railroads that will operate near the Southwest route.

Transit planners said "additional amendments" will be required to "continue services" on construction of the line, an extension of the Green Line.

It's unclear how much the future additions will cost. In April 2018, $2 million was added to the AECOM contract.

Back in 2012 when Southwest was in the throes of the planning process, the project was slated to cost $1.25 billion, with passenger service beginning in 2018. Now, service is slated to start in 2023.