(Bloomberg) — Private equity firms, which three years ago became subject to oversight by the Securities and Exchange Commission, have fixed some of their worst deficiencies although their transparency could still improve, an SEC official said.

"The pace of change has been surprising," Igor Rozenblit, the agency's co-head of private-funds compliance inspections and exams, said at a conference today in New York. "I don't think we're there yet, but transparency has improved markedly. Some of the more objectionable issues are just ending."

The SEC last May shocked the industry by saying it found illegal fees or severe compliance shortfalls in more than half of the firms it examined since starting a review of the $3.8 trillion market in 2012. The agency, which ended its initial examinations in October and is working on a report about its private equity findings, will also start looking beyond buyout managers at firms that invest in similar alternatives to stocks and bonds, Rozenblit said.