The Securities and Exchange Commission is pushing to suspend Standard & Poor's from rating commercial mortgage bonds, according to a new report.
Citing a single source with knowledge of the matter, Bloomberg reported the rating firm's parent company, McGraw Hill Financial, is still negotiating a potential settlement with the SEC despite the threat of a suspension. The federal agency has been investigating whether S&P altered its rating criteria to gain customers in 2011.
McGraw Hill's stock fell as much as 4.3 percent after the Bloomberg report and finished the day down about 2 percent.
The issue of a suspension had been the focus of the settlement discussion, Bloomberg quoted its source as saying, with S&P arguing that such a penalty would have major consequences to its reputation.
A spokeswoman for S&P declined comment to CNBC, and the SEC did not immediately return calls for comment.
In October, McGraw Hill said it was in "active" settlement talks with regulators over the rating of six commercial mortgage-backed securities. The company took a $60 million charge in its third quarter to prepare for any possible settlement on that front.