The Federal Communications Commission is scheduled today to authorize the nearly $80 billion proposed merger of AT&T Inc. and BellSouth Corp., one day after the Department of Justice approved the deal.

But by late Wednesday afternoon, FCC commissioners were still haggling over possible conditions, indicating the transaction may take longer to get approved, a source close to the agency said. As of late Wednesday afternoon, the merger was still scheduled for the commission’s meeting this morning but there was a strong possibility the vote could be postponed to later today or perhaps for a few days.