The head of the board that owns and operates Charleston International is demanding further cuts in the $159 million construction estimate for redeveloping the airport’s aging passenger terminal.

Charleston County Aviation Authority chairman Andy Savage lashed out Thursday at the program manager for not doing enough to lower the figure to $153 million.

Speaking at a public meeting, he urged the firm, Michael Baker Corp., to be a “more potent advocate” for the airport.

“We will accept nothing less,” Savage said, reading from a letter he sent to the company in May.

He urged the firm to work with the architects and construction team to find the $6 million in savings before a June 20 board meeting.

If not, Savage said, the board “will likely see Baker as deficient in its efforts to meet its commitment to the authority. I do not want that to happen.”

The Charleston defense lawyer also called out other firms the airport has hired to shepherd the project, saying the airport is paying them millions of dollars without seeing tangible results on the expense front.

“I don’t understand the unwillingness to reduce margins of profit and to do what can be done by those we have hired to contain cost,” Savage said at Thursday’s meeting.

The airport has been trying to close a $19 million gap in terminal improvement costs since May, It needs to come up with a firm price before the Aviation Authority can issue $176 million in bonds in August to pay for most of the makeover.

The construction team has already eliminated several, mostly cosmetic items, such as quartz counter tops, without affecting the overall scope of the project.

The revamped terminal will be expanded to include six new gates, a third baggage carousel, a new rental car pavilion and other changes. The work should be completed in 2015.

The $159 million construction estimate goes to the full authority for final approval later this month. The figure includes about $12 million for unplanned work that could crop up as demolition crews begin tearing apart the building.

The price does not include extras for professional services. Those amount to $30.3 million, bringing the total price to $189.3 million.

The $13.3 million difference over the amount to be borrowed will be funded by the Aviation Authority, said Sue Stevens, airports director.

Reach Warren L. Wise at 937-5524.