"We are throughout the day in contact with those firms," checking in "on a very regular basis," Cox told reporters after appearing at a Capitol Hill press conference with newly released Chinese political prisoner Yang Jianli. He said market regulators are eyeing liquidity and other issues given the recent market turmoil prompted by concerns about poor-quality "subprime" lending.

Credit-rating agencies have come under fire for giving high-quality ratings to some mortgage-backed securities larded with poorer-quality loans, something Cox said won't be ignored as the SEC begins inspecting rating firms under new authority granted by Congress last year. Lawmakers gave the SEC new authority to regulate firms such as Standard & Poor's, a unit of McGraw-Hill Cos., and Moody's Investors Service, a unit of Moody's Corp., under a law that also sought to bring new competition into the rating business.

While Cox stressed that the SEC won't "second-guess" ratings, he said rating firm procedures "will almost certainly be incorporated in normal inspections" of rating firms. The SEC's ability to inspect such firms is new and will be forward looking, with the exception of investigations into possible securities-law violations, Cox noted.