The Maryland Department of Transportation has delayed a vote on a plan to have a private company design, build, operate and help pay for a light-rail Purple Line , a spokeswoman said Tuesday night.

The state’s Board of Public Works — made up of the governor, the comptroller and the state treasurer — was scheduled to vote Wednesday on the transportation agency’s plan for a public-private partnership. MDOT needs the board’s approval to solicit companies interested in a 35-year contract to design, build, operate and help finance the proposed 16-mile rail line between Montgomery and Prince George’s counties.

Erin Henson, an MDOT spokeswoman, said in an e-mail that the agency is “taking a little more time to craft the solicitation” and will instead take it to the board Nov. 6.

The proposed public-private partnership would be one of the most far-reaching of any U.S. transit project because it would rely heavily on private financing.

State transportation officials say they anticipate a team of companies would contribute $500 million to $900 million toward a Purple Line’s $2.2 billion costs. The state would reimburse the private team for construction costs over five years and then pay the company to operate and maintain the line for 30 years.

Map of the proposed Purple Line