Developers of the old Boston Garden site now want to build three high-rises with residences, hotels, offices and shops — possibly with a supermarket and cinema — that would tower over the TD Garden, according to expanded filings released by the Boston Redevelopment Authority yesterday.

Developers originally unveiled plans for twin towers in May but have since reconfigured the space, and the three-tower project was released formally to BRA officials yesterday.

“We’re excited,” said Susan Elsbree, spokeswoman for the Boston Redevelopment Authority. “This is a project that’s been a long time in the making.”

The three proposed towers where the old Garden once stood — now a parking lot in front of the current Garden — would include a 600-foot residential tower with 497 units. A 306-room hotel in the middle would stretch 320 feet. An office tower next to it would rise to 420 feet.

All totaled, the project would include 668,000 square feet of office space, 142,000 square feet of flex office space, 235,000 square feet of restaurant and retail, 25,000 square feet for an atrium hall leading toward Canal Street and a 40,000 square foot expansion of the TD Garden, primarily for concessions and an elevator lobby on levels 3-7, according to the filings.

Some 800 parking spaces would be built underground.

The project “may include” a grocery store and pharmacy and a cinema on the upper floors, though no companies were mentioned.

Boston Bruins principal Charlie Jacobs told the Herald in May that a Target, once a rumored possibility, is not slated for the site.

The first phase — the retail base, hotel tower and Garden expansion — would begin in late 2014 and end in early 2017. The rest of the project would then take about two to three years.

The project is a collaboration between Boston Properties, which owns the John Hancock Tower, and Delaware North Companies, which owns the Boston Bruins. Both companies declined to comment yesterday.