MARTA has postponed an appearance before the Atlanta City Council over the objections of council members — a sign of continuing strained relations between the transit agency and city officials.

MARTA was scheduled to appear before the council’s transportation committee Wednesday for a routine briefing on its operations and plans to build new transit lines in Atlanta. But CEO Collie Greenwood notified committee Chairman Amir Farokhi on Friday that MARTA would reschedule the briefing.

Greenwood cited ongoing negotiations over a proposed audit of MARTA’s Atlanta expansion program. With the scope and terms of the audit not yet finalized, Greenwood said it would be prudent to postpone the briefing.

“I look forward to a productive conversation with the members of the transportation committee in the near future,” Greenwood wrote Friday in a letter to Farokhi.

Farokhi responded that same day, asking Greenwood to proceed with the briefing. He said the status of the audit “does not preclude MARTA’s ability to provide — nor the City Council’s need to receive — a quarterly report.”

But Greenwood subsequently confirmed to Farokhi that it will not appear before the committee Wednesday. The agency declined to comment Monday.

The move drew criticism from Council President Doug Shipman and from MARTA board member Rod Mullice, who represents Atlanta.

“I don’t think the pending audit has any bearing on their regular reporting to council,” Shipman said.

Mullice called Greenwood’s letter “unfortunate.”

“It’s important for MARTA to be accountable and go out of its way to be transparent,” he said.

The dust-up is the latest sign of strained relations between MARTA and the council. Council members have grilled Greenwood for months about the status of MARTA’s plans to build new transit lines in Atlanta.

In March the agency announced it was prioritizing nine of 17 planned projects amid a revenue shortfall, but it has no specific timetable for completing the remaining projects.

When the council unanimously approved a resolution calling for an audit of the expansion program, MARTA blasted council members for “playing politics” and urged them to “get out of the way and let MARTA deliver the projects.” MARTA later sounded a more conciliatory tone, and — with Mayor Andre Dickens’ endorsement — the audit appears to be moving forward.