BLOOMINGTON — The Mall of America is advancing plans for a $200 million expansion that could add a second hotel, more space and a medical office tower.

It’s a small step in the Bloomington megamall’s long-planned, often-delayed expansion.

“It’s the next piece that we’re trying to assemble and get financed and move forward with,” said Kurt Hagen, senior vice president of development for mall owner Triple Five Group.

If plans develop according to schedule, expansion could start next spring, he said.

Six years ago, officials unveiled an ambitious expansion plan that would have doubled the size of the megamall, but that plan stalled. The new strategy is more measured steps.

Rochester’s Mayo Clinic has expressed interest in joining the latest project, which could include 150,000 square feet of medical space. Hagen said both parties are “still exploring” what Mayo’s presence would be, including an option for a medical office tower.

“The building itself could be more than Mayo Clinic,” Hagen said. “Mayo is focused on a wellness facility here. They’re not focusing on a hospital.”

A Radisson Blu hotel is already under construction on the south side of the complex. Expansion plans also call for another hotel, although its size hasn’t been decided, Hagen said.

“Depending on the type and the brand of hotel we choose, that will help us determine the right room count,” Hagen said.

The plan also calls for three levels of additional retail space, as much 200,000 square feet added to the 4.2 million square feet of space the megamall already boasts.

“We’d like to take it higher-end retail,” Hagen said. “All these pieces kind of tie together — the flag and brand of the hotel, the services that Mayo is offering and the type of retail this wing will cater to.”

The project could be 13 to 15 stories high, Hagen said, most likely with retail on the lower floors and medical and hotel rooms higher up.