The developer of a large shopping center proposed for Main Street in Westbrook has sliced a little square footage from his buildings without scaling back on his plans.

Jeffrey Gove said he plans to build 500,000 square feet of retail space on the property, which also abuts Larrabee Road and is now a gravel pit operated by Pike Industries. The land is on the Portland-Westbrook town line, across Main Street, or Route 25, from a shopping center anchored by Kohl’s.

Gove’s initial proposal called for 580,000 square feet of space, but issues with wetlands on the property led him to reconfigure the layout of six large buildings and a couple of smaller structures in the center, he said. Most of the reduction in square footage came from designing slightly smaller buildings, he said, not by eliminating buildings.

Gove has yet to sign major tenants and won’t say who is considering moving into the space. He said tenants like to make their own announcements, which could come as soon as next month.

But rumors of potential tenants have swirled and include Market Basket, the Massachusetts-based supermarket chain, which said in 2014 that it expected to open more Maine stores following the success of its Biddeford supermarket; and Costco, the warehouse retailer based in Washington state. In his initial sketch of plans for the site submitted to the city this year, Gove labeled one building a 148,000-square-foot “wholesale club.”

In his revised plan, buildings are only designated for retail, banks and restaurants.

Calls to Market Basket and Costco were not returned Wednesday, but Mark Malone, of Malone Commercial Brokers, said those two companies are high on the list of likely tenants. Malone’s company is not involved in the development, but he presented a forecast of retail development in greater Portland at the January conference of the Maine Real Estate and Development Association.

About a decade ago, Costco had looked at the shopping center that’s anchored by Cabela’s in Scarborough, just off exit 42 on the Maine Turnpike, but opted not to build there, Malone said. The chain’s closest location is in Massachusetts and it recently announced that it plans to add 150 of its warehouse club stores in the next five years.

Market Basket, Malone said, has made clear that it wants more than just the Biddeford store. The company’s expansion plans in Maine, Massachusetts and New Hampshire were slowed by last year’s turmoil that split the family ownership of the chain. Now that the drama is gone, the company is expected to resume adding stores, Malone said.

Other options, he said, include Hobby Lobby, the arts-and-crafts chain that has stores in Auburn and Bangor. He said outdoor retailer REI also is considered a likely tenant, but it probably wouldn’t take one of the larger buildings in the shopping center.

The two largest structures for individual stores are 148,000 square feet and 167,000 square feet, although the plans that Gove has submitted are preliminary and non-binding, said Molly Just, Westbrook’s city planner.

Just expects Gove will meet with her and other city officials in the next few weeks to get preliminary reactions to the plans. Gove also has met informally with state transportation officials and will likely need to do a traffic study, said Ted Talbot, a spokesman for the Maine Department of Transportation.

Just said the property – which Gove has an option for, but probably won’t purchase until he gets all the permits he needs to start construction – is appropriately zoned for the use Gove envisions. It covers roughly 57 acres.

Approval will likely require workshops with the city’s planning board, a neighborhood meeting, a formal site plan and then a final vote by the board. Barring any major problems, she said, that could be done in time for Gove to start work late this winter.

Construction would probably take a year to complete.

Gove said much of the site has marine clay, which means he will use piles under concrete slabs to support the buildings, rather than just slabs.

“Marine clay is like toothpaste in a tube,” Gove said. “It settles and retains moisture.”

Similar soil in Biddeford forced the Kohl’s department store on Alfred Street to close last year. One corner of that store, which was built on a concrete slab, sank a couple of inches. Ceiling tiles loosened and some doors would not close properly.

The chain rebuilt the store, which was closed for about seven months.

Gove believes the time is right for a major new shopping center in the Portland region, with the economy rebounding and the low cost of gasoline and heating oil giving people more money to spend.