The ultimatum was delivered after state authorities decided not to contribute.
ESPN reports that MLB chief operating officer Bob DuPuy said in a letter to local government leaders that baseball won't issue a letter of credit to cover cost overruns on the project, and reiterated that the Marlins can't stay in the open-air Dolphins Stadium for the team to have long-term success in South Florida.
The letter doesn't say what the consequences are for missing the deadline, but team officials met in Las Vegas with Mayor Oscar Goodman five months ago, and Goodman is trying to lure a franchise to his city.
"The Marlins are one of the only teams currently expected to continue losing money through 2006," the letter dated May 12 states.
"We must collectively provide [commissioner Bud Selig] with the Marlins' path to financial stability."
The two-time World Series winners want to build a $420million, 38,000-seat retractable roof stadium next to the Orange Bowl near downtown Miami. The team insists that their proposed park would mean no more delays caused by Florida's rainy summers, possibly leading to better attendance, increased revenue and a higher payroll.
The Marlins have played at Dolphins Stadium - formerly known as Pro Player Stadium - since their founding in 1993, but they have said they might move without a new ballpark.
City and county officials pledged $166million toward the ballpark, and Marlins owner Jeffrey Loria agreed to pay $192million rent. A $32million parking garage was expected to pay for itself, leaving a $30million funding gap to be plugged by the state.
"At this point, none of the parties have indicated a willingness to increase the level of their current contribution for the project," Burgess wrote. He added that an alternative may be to "reduce the cost and scope of the project".
