Developers interested in redeveloping the Historic Gas Plant District, home to Tropicana Field, are rolling out their rosters of partners for the project.

A 30-day window to submit proposals opened Jan. 4. Instead of issuing criteria and benchmarks, Mayor Ken Welch instead opted to invite competing pitches in response to an unsolicited proposal made in October by Ark Ellison Horus.

The city’s third attempt to develop the Gas Plant in recent years was originally scheduled to start before Thanksgiving. It was postponed under pressure from interested developers and City Council members. Proposals are due Feb. 3 by 10 a.m.

On Monday, Ark Ellison Horus, a team made up of Ark Investment, Ellison Development and Horus Construction, announced a slate of partners.

The group includes construction company Moss, architecture, infrastructure and engineering firm Jacobs and engineering, planning and design services company Kimley-Horn. The Pinellas County Housing Authority, the St. Petersburg Housing Authority and Evara Health also have signed letters of intent to be part of their $6.8 billion vision for the redevelopment, Ark Ellis Horus announced.

“These are well-known, trusted companies with deep experience delivering complex, transformative projects,”said Casey Ellison, CEO of Ellison Development, in a statement. “Each brings unique and extraordinary value, and their interest strengthens the original plan and our ability to deliver lasting impact for St. Petersburg residents.”

The Pinellas County Housing Authority submitted its own unsolicited proposal to build a senior housing tower on a half acre on the Lot 3 parking lotat the Trop.

Moss recently acquired Ellison Construction. Ellison told a reporter last week that has no bearing on Ellison Development and the two are separate companies.

Similar to what the Tampa Bay Rays did when they were interested in redeveloping the Gas Plant, members of the Ark Ellison Horus team gave a presentation last week to the Campbell Park Neighborhood Association. It didn’t go over smoothly in an audience that included mayoral candidate Maria Scruggs and community members who oppose what they view as a rushed process to find a developer.

“I feel like it’s being forced down our throats,” said former Campbell Park neighborhood association president Lisa Thomas.

Blake Investment Partners on Saturday announced it is joining forces with local affordable housing provider Blue Sky Communities. Blue Sky is behind Skyway Lofts, Bear Creek Commons and senior tower Peterborough.

Local investor Thompson Whitney Blake, who in March offered $260 million in cash to purchase the entire Gas Plant site, said Blue Sky will handle all affordable and workforce housing on site and privately off site. He said his group has identified five submarkets and would start tying up properties for affordable housing over the next decade.

“There are places in the city where today we can go and find density and build affordable units, help the community and make money,” Blake said. “We’re going to start doing things that make pragmatic sense as part of a bigger portfolio.”

Blue Sky Partner and CFO Scott Macdonald said his group fielded calls from other developers who are interested in the Gas Plant site, but after evaluating the landscape of players, went with Blake.

“His team is the right team to lead this from what I’ve seen and the partners he’s bringing to the table,” Macdonald said. “When you look at some of the stalled development in our city, in general, they’ve been led by people who were not real estate developers or didn’t have extensive real estate experience. Those are important to me to make sure we were partnering with someone who wasn’t going to let that happen again.”

John Catsimatidis, the CEO of Red Apple Real Estate and the New York billionaire behind the Residences at 400 Central, St. Petersburg’s tallest tower, has said he is also interested in developing the Gas Plant land. He and Troy Simpson, president of the mixed-use division of Delray Beach-based Kolter Group, asked the city to extend its timeline.

“We remain very interested in this process and may either submit a proposal or enter into a strategic partnership,” Catsimatidis said in a statement. “Our top priority is making sure St. Pete becomes an even greater place to live because of this.”

When asked if Kolter still planned to submit a proposal, Regional President Brian Van Slyke told the Tampa Bay Times on Monday that his company was “still discussing it internally,”

”It’s a large undertaking,” he said. “Obviously Kolter has the ability and the strength and the various business verticals to accomplish something like that. We’re trying to evaluate if it fits our growth plans.”

Johnny Saye, co-founder of Stale Chips, emailed the city to say his firm is working on a proposal with architectural firm DPZ CoDesign.

According to its LinkedInbusiness profile, Stale Chips provides customized workshops and coaching to government departments, nonprofits, Fortune 500 companies and startups. DPZ CoDesign worked on Rosemary Beach, a planned community in Walton County.

“As this is a small window, we appreciate any urgency and help,” Saye wrote, asking for guidance on the structure of their proposal. He did not respond to a call and email seeking comment.

Time staff writer Rebecca Liebson contributed to this report.