Memo to bidders competing to buy Philadelphia Gas Works: Put a lid on it.

City Councilwoman Marian B. Tasco complained Tuesday that lobbyists purporting to represent bidders for the city's gas utility have reached out to her and other Council members, apparently in violation of confidentiality agreements to keep the sale process secret.

"I have a problem with being contacted by individuals," Tasco said at a meeting of the Philadelphia Gas Commission, the city's oversight board that she chairs.

Suzanne Biemiller, Mayor Nutter's first deputy chief of staff, agreed with Tasco and said the bidders, whose identity the city has declined to disclose, would be instructed that "they are not to be contacting City Council members as individuals. . . . That is the last thing we would want."

It is not entirely clear who was contacting whom, and to what purpose.

The Nutter administration is in the final phase of a yearlong process to sell PGW, a transaction that could be worth up to $1.8 billion. The vetting process is being handled internally by a handful of senior city officials, plus a broker, J.P. Morgan, and the city's financial adviser, Lazard Frères & Co. L.L.C.

The finalists will receive PGW management presentations this month before making final proposals in January. The mayor plans to announce his choice in early February. City Council then will vote on the deal, up or down.

"We don't have any role in the selection process," said Tasco, who participated in the meeting by a conference call and declined, through a spokesperson, to identify which bidders were making contact.

Biemiller told the commission she was unaware of any lobbying efforts by bidders. Tasco expressed disbelief.

"Everyone else in the city knows this was going on," she said.

"Maybe they didn't want us to know because we would have forbidden it from happening," Biemiller said.

Guessing which utilities or private equity firms are vying to buy PGW has turned into a City Hall parlor game.

"I should say there are certainly many rumors floating around the city," Biemiller said. "We certainly haven't confirmed any of those rumors.

"You can't keep people from talking and speculating, but the bidders themselves are eager to keep their names confidential at this point."

A Philadelphia Board of Ethics inquiry could be initiated if someone were found to have broken a confidentiality agreement, Biemiller said. But it was not clear that it would preclude a bidder from participating.

"We don't anticipate that happening," she said.