NEW YORK — A large private equity firm is poised to enter the scrap market with its proposed acquisition of a Philadelphia scrap processor.

Boston-based Audax Group has expressed interest in acquiring nonferrous scrap processor Thalheimer Brothers Inc., according to a recent filing with the Federal Trade Commission.

The group’s Audax Private Equity Fund IV LP was granted early termination of the waiting period required under the Hart-Scott-Rodino Antitrust Improvements Act, according to an FTC notice filed in November.

The companies didn’t respond to a request for comment, but a source familiar with the development confirmed that both groups are in talks.

"(Audax has) been looking at a scrap acquisition for a long time. They were trying to do a scrap deal and looked at two other companies before this. They dug into them but decided against (the first two companies)," the source said. "They see scrap as a real industry and like the consolidation strategy."

The source suggested that Audax has no intentions of shaking up management at Thalheimer should the deal be completed.

According to its website, Audax Private Equity was established in 1999 as a source of equity capital for small-cap and lower-middle-market companies. It is now investing out of its third private equity fund, which has more than $1 billion in capital.