TAMPA — The developer of the SkyPoint and Element high-rises is talking to City Hall about building a riverfront apartment tower up to 35 stories tall next to the David A. Straz Jr. Center for the Performing Arts.

A joint venture between Greg Minder of the Intown Group and Phillip Smith of the Framework Group has proposed paying $4 million — subject to terms and conditions being negotiated with the city — for city property behind the annex to the John F. Germany Public Library.

As proposed, their $88 million project would include ground-floor space for stores, restaurants and Straz offices, practice spaces or other arts center operations. Rising above that, developers envision an Art Deco tower with 350 apartments. The project also would include up to 600 parking spaces, with a pool and fitness center above the parking deck.

But many details, starting with the exact boundaries of the potential development site, need to be worked out between the city and the development team.

"We are just at the beginning of the process," Mayor Bob Buckhorn said Monday. "It is a very tight site. It is a complex site. . . . That's city property, and we're not going to move on it until we're comfortable and may decide not to do it at all."

Still, the developers like the idea of building a big residential project so close to the Straz, the Riverwalk, Curtis Hixon Waterfront Park, the Tampa Museum of Art and the Glazer Children's Museum.

"All of that comes together really nicely in a living, working and playing environment unsurpassed in Tampa," Minder said.

Intown first discussed an idea — for a different project, Minder said — with the Straz in 2006. That never gained traction, but the developers have remained interested in the area. And the performing arts center has long-standing needs for more meeting space, office space and parking, Buckhorn said.

This summer, Tampa officials decided to test the market and put out a request for proposals for a triangle of property behind the library annex.

In its request, the city said it was open to selling the property behind the library where Tyler and Cass streets come together. The site included an intersection in front of the entrance to the Straz, two landscaped medians and a curve where one-way traffic heading west on Tyler goes to the left to head back east on Cass.

The city's goal was to stimulate activity in nearby parks and museums, as well as provide parking for library patrons. To do the project, the city said it needed experienced developers.

In response, City Hall got just one proposal, from the Intown-Framework team. The president of each company is associated with big projects in Tampa. Minder teamed up with an Atlanta developer for the 32-story SkyPoint and 35-story Element residential towers. Smith is currently developing the 350-unit Varela apartment complex at Lois Avenue and Spruce Street in West Shore.

In a 67-page plan, the developers proposed a site that doesn't quite overlap with the city's triangular site. Instead, it's a rectangle that would take in the end of the driveway out of the Straz, along with part of Tyler Street.

Using the site that's proposed would mean reconfiguring the streets in that area into a more traditional grid, an idea Buckhorn says he would entertain. One goal of the design, according to the proposal, is to slow incoming traffic on Tyler to improve the experience of Straz patrons as they go to and from the center.

Because the outline of the site is still being negotiated, Minder said it's too early to say how the project might affect an elevated walkway between the William F. Poe parking garage and the Straz. But he did say developers are not proposing to demolish or tie into any existing buildings.

The schedule is likewise uncertain. If the parties came to terms by the end of this year, the developers outlined a schedule that would have the tower open in the third quarter of 2014.

But there's no rush, Buckhorn said.

"It's our property," he said. "We're going to move on our time frame."

Times staff writer Drew Harwell contributed to this report. Richard Danielson can be reached at Danielson@tampabay.com or (813) 226-3403.