An already-sweeping rewrite of the city of Pittsburgh's rules on campaign finance got broader yesterday, and council members gave themselves two weeks to think through the implications before voting on the expanding package of reforms.

Mayor Luke Ravenstahl expressed concerns about, and interest in, the emerging bill.

The legislation, authored by Councilman William Peduto, would put the same contribution limits on candidates for city office that apply to federal candidates. Starting in 2010, they could accept no more than $2,300 from any person or partnership, and $5,000 from any political action committee, in the run-up to a primary, general or special election.

Councilman Ricky Burgess introduced an amendment to require that candidates disclose any contributors who have done business with the city or its authorities in the last five years, or have relatives who have done business with those entities.

"What we're trying to get at is the appearance -- real or perceived -- of quid pro quo relationships," said Mr. Burgess. He said full disclosure of contributors' interests in city business would "take the politics of contributions out of the system."

Council President Doug Shields said he doesn't want to create so much paperwork that no one dares to run. But he backed the amendment, with the understanding that the language will be reworked before passage.

The amendment passed 6-1, with Jim Motznik voting "no" and Dan Deasy and Tonya Payne out of the room. Council then postponed its vote on the full bill.

Mr. Ravenstahl has backed online disclosure of campaign donations. But he has concerns with donation limits.

"I would like to see campaign finance reform done at the state level, because it puts it on an equitable playing field," he said. "But we'll take a look at it, and I think Pittsburgh needs to lead by example. We have to do something, and I look forward to having a conversation with council to decide what that might be."

Mr. Ravenstahl, Mr. Peduto and other council members have received five-figure campaign donations in past races.