INDIANAPOLIS (AP) Expansion plans call for the Indiana Convention Center to grow to more than 1.1 million sq. ft. and be connected by tunnel to the city’s new retractable-roof stadium.

The planned $275-million expansion would add approximately 420,000 sq. ft. to the current facility in downtown Indianapolis, according to preliminary plans presented Nov. 13 to the city’s Capital Improvement Board.

The convention center expansion is part of the approximately $1-billion project that includes construction of the 63,000-seat Lucas Oil Stadium that will be home to the Indianapolis Colts and host events such as the NCAA basketball Final Four.

Plans are for the RCA Dome to be demolished in 2008 after the new stadium opens, with that space being used for the convention center addition.

David Frick, chairman of the Indiana Stadium and Convention Building Authority, said the expansion would move the convention center from among the top 30 such facilities across the country into the top 15.

“Probably first, second or third amongst cities we compete with, and it will have a tremendous economic impact throughout the state of Indiana,” he said.

The design plans call for the addition to be two levels and for an underground tunnel connecting it to the new stadium, which also could be used for convention space.

Construction work began last year on the $675-million stadium.