Channel Club, the long-anticipated apartment tower and Publix Super Markets Inc. store in Tampa's Channel district, is inching closer to vertical construction.

Mercury Advisors, the developer of the Channel Club, and KAST Construction are close to signing an agreement, Ken Stoltenberg, principal of Mercury Advisors, said Tuesday.

"We are working diligently to finalize all the contracts with KAST and other vendors," Stoltenberg said.

A contract will likely be finalized within weeks, Stoltenberg said.

KAST signs have been erected on the vacant block between East Twiggs and Madison streets. Page McKee, vice president of the Tampa business unit for KAST, confirmed that the company was finalizing its contracts with Mercury Advisors.

Signing a general contractor is a major step forward for Channel Club, which has been in the works for years. The 21-story, 323-unit apartment tower will break ground first, and once that's topped out, the Publix will begin construction.

McKee said that if all goes according to plan, work on the tower could begin in early to mid-September. Pre-construction work, including tests and measuring to make way for a deep shaft foundation, are underway on the site.

West Palm Beach-based KAST opened an office in Tampa this summer. Channel Club will be its second major project in the Bay region; it is also the general contractor of ONE St. Petersburg, a 41-story condominium tower in downtown St. Pete.