JACKSON (AP) — A construction company with black ownership has filed a federal civil lawsuit against Gov. Haley Barbour, employees of the Mississippi Development Authority and Toyota of North America, claiming racial discrimination in the building of a new plant in northeast Mississippi.

The owners of Fish & Fisher, Jacqueline Williams and Renna Fisher, say Barbour, MDA and the car company acted in concert to bar them from participating in what they claim was a whites-only bid process for site preparation.

L&T Construction won the $49 million contract and is not named as a defendant in the suit. But a lawyer for Fish and Fisher said that company may have won the contract under questionable circumstances, while the contractor he represents was qualified by both the state and Toyota to bid as a minority-owned company.

Fish and Fisher eventually took a subcontracting job at the site in Blue Springs. Owners seek an injunction and damages.

‘‘Understand the dynamics at work here,’’ said Byron Perkins, the Birmingham, Ala., attorney representing Fish and Fisher. ‘‘Subcontracting is like sharecropping. You’re qualified to do the same work as a general contractor, you’re just getting paid less — substantially less.’’

A Toyota spokeswoman called the claims ‘‘baseless’’ and touted the company’s commitment to hiring minority companies during the construction process.

‘‘Toyota’s got a track record nationally as well as in Mississippi of awarding much work to minority companies,’’ said Barbara McDaniel, a spokeswoman at Toyota’s North American manufacturing headquarters in Kentucky.

She said the company has spent more than $40 million so far with minority companies on construction at the site in the areas of site preparation, foundation work and construction of the steel buildings.

A statement from the company says Toyota has exceeded its goal to spend 15 percent with minority businesses on the project. It also noted Toyota is one of 14 companies in the U.S. that belongs to the Billion Dollar Roundtable, a designation received for spending more than $1 billion annually with minority suppliers.

Barbour’s spokesman Dan Turner said the governor is aware of the suit.

‘‘There’s no basis whatsoever for a lawsuit against the state, MDA or officials,’’ he said.

That’s also the opinion MDA executive director Gray Swoope, who issued a statement on the lawsuit. A message left with L&T seeking comment from an owner or company officer was not immediately returned.

Toyota was expected to begin producing hybrid cars at the plant in late 2010. Construction of the building is mostly complete and about 100 employees are at work in the administration building. But Toyota has since put the project on hold because of the economy.

The lawsuit claims Barbour, MDA and Toyota conspired to exclude minority-owned companies by holding a private bidding process, depriving Jackson-based Fish and Fisher’s owners of their constitutional right to equal access.

Perkins said they also believe Toyota erred by allowing Hernando-based L&T to keep the contract after a partnership it formed with another white-owned business dissolved shortly after the companies won the contract. The suit claims L&T didn’t meet the guidelines set out for the project by Toyota and that the company was not bonded.

Perkins argues Fish and Fisher would have had no such problems.

‘‘This isn’t a fly-by-night company,’’ he said.