MIAMI — The Florida Marlins can start construction on their new stadium.

Miami-Dade County commissioners voted 9-3 early Wednesday morning to pay for the sale of bonds for the ballpark after the Marlins pledged to pick up a possible $6.2 million shortfall.

County Manager George Burgess told commissioners that the $306 million to pay for the bonds was off by $6.2 million because of a higher interest rate. Marlins president David Samson told the commission that the club would pay for the difference and not scale back the project.

The $515 million retractable-roof ballpark is expected to open for the 2012 season in the city's Little Havana neighborhood on the site of the demolished Orange Bowl. A formal groundbreaking is scheduled for July 18.