A Charleston County Aviation Authority board member has resigned amid an airport contract flap involving his business.

Joseph H. Jefferson III stepped down Thursday, according to a copy of his resignation letter obtained by The Post and Courier.

Jefferson could not be reached for comment Friday.

“This decision is mine alone, and has not been suggested to me by anybody,” he wrote Aviation Authority Chairman Chip Limehouse on his company's letterhead.

Limehouse said late Friday he had not seen the letter but that Jefferson called him to tell him he had written it.

The resignation followed the authority's decision last month to negotiate a construction management contract with a Texas company forthe $150 million expansion of Charleston International Airport.One of the other bidders has since contested the selection, saying the process was tainted because Jefferson has business ties to the winning group.

The authority unanimously voted on March 22 to enter talks withDallas-based Austin Commercial LP and its local partner, HittContracting Inc.

Jefferson said in his resignation letter that his firm does not have a formal contract with the top bidder. Rather, Palmetto Civil Group has “an informal expectation that should Austin/HITT be awarded a contract for the Project, PCG would be considered for work assignments consistent with its area of competence and experience,” he said.

As a board member, Jefferson said he resigned from the airport committee that was spearheading the expansion plan in early December when it became “obvious” his company might have an opportunity to work on the project.

He also said he distanced himself from all discussions about the expansion and never participated in any deliberations about the contract selection.

Jefferson disclosed his relationship with the Austin-Hitt group to Limehouse and recused himself in a letter dated March 22, the day the contract was awarded.

In resigning, he said his relationship with Austin-Hitt would require further recusals and that it would be appropriate for him to step down from the airport authority.

“I am confident that I have complied, in letter and in spirit, with all applicable ethical requirements,” he wrote.

EDITOR'S NOTE: Previous versions of this story contained an error. The Charleston County Aviation Authority did not award a contract on March 22 to Austin Commercial LP and Hitt Contracting Inc. but voted to negotiate a contract with the companies. The Post and Courier regrets the error.

Reach John P. McDermott at 937-5572.