This is a rendering of what a light-rail Purple Line train would look like running through the University of Maryland campus in College Park.

A Metro board committee voted Thursday on an 11th-hour measure that could delay a multimillion-dollar land transfer critical to the construction of Maryland’s light-rail Purple Line.

Metro is expected to hand over to Maryland the land rights to properties at New Carrollton, College Park and Silver Spring Metro stations so Purple Line work crews can begin construction. The properties are valued somewhere between $24 million and $37 million.

Maryland wants the rights to those stations in exchange for a 450-space state-owned parking lot and a plot of state land, valued together at $17.1 million.

But Thursday, members of the board’s capital planning and real estate committee said they’re concerned that Metro is being underpaid in the exchange. In a surprise move, the committee passed a substitute resolution that gives tentative approval for the transfer of property rights — but only if officials from Metro and Maryland enter negotiations and come up with a new figure for “fair compensation” on the exchange.

The new resolution mandates that an agreement on fair compensation must be decided by the end of December. It will go to a final vote before the full board in two weeks. Maryland is scheduled to begin construction work at College Park station in early November.

“No one argues that the Purple Line is a bad project. It’s a very good project, and people are very excited about it,” board member Paul Smedberg said. “But given the financial situation of the organization, we want to make sure that we’re fairly compensated.”

“We’ll do what we can to help our partners” building the Purple Line, said Steve McMillin, the newly-appointed chairman of the committee, “but [Metro] has interests to protect, and we as board members have a responsibility to protect them.”

Board member Robert Lauby said the current deal failed to account for the future potential value of the property — particularly if developers wanted to pay for the rights to build above the station.

“It seems to me that we don’t have a full assessment of what the cost is, and that’s a little disturbing,” Lauby said. “It’s non-revenue producing land now, but is it always going to be? … We need to take a good hard look and understand what exactly we’re transferring here.”

Notably absent from the meeting: Board members Corbett Price and Jack Evans, who said Wednesday night that they would veto the land-transfer proposal– scheduled for a final vote in two weeks —  for an unrelated reason. They want to use the property-rights issue as a bargaining chip in exchange for Maryland’s support for their proposal to restructure the board.

Board members’ concerns about the fairness of the swap came in despite of General Manager Paul J. Wiedefeld recommendation that the board approve it, citing the potential benefits the new 16-mile light-rail line would bring Metro — namely more riders.

“To me, it makes a lot of sense that we move forward with this as quickly as possible, for the sake of our region and for our riders,” Wiedefeld said.

Maryland representatives on the board, particularly Michael Goldman and Malcolm Augustine, expressed outrage that their colleagues would put the project at risk. Goldman suggested that other board members were trying to nickel-and-dime the state of Maryland, and that Metro’s real estate experts failed to take into account the many ways that Maryland provides financial and infrastructure support to Metro.

Augustine said the last-minute attempts to renegotiate the land exchange could put more obstacles in front of completion of the Purple Line.

“It takes nerve for Metro to ask for money back for land that came from the state of Maryland,” Augustine said. “I find that a little tough to take.”

“There have been tremendous roadblocks that have occurred,” he added. “I would really hate for Metro to become another one of those roadblocks.”

After the meeting McMillin acknowledged that it’s possible that the board’s decision could result in a delay for the project. But ultimately, he said, as a Metro board member, it’s not his job to worry about that.

“We are trying to act expeditiously … but we are not responsible for the timeline for managing this particular project,” McMillin said.

“I don’t know when they thought they would get these types of questions considered, vetted and debated,” McMillin added, “but presumably when you’re managing a project you try to do that well before the beginning of construction.”