Arthur Levitt, the former chairman of the U.S. Securities and Exchange Commission, said he will leave his role as a policy adviser to Goldman Sachs Group Inc. at the end of the year.

Levitt, 83, took on the position in June 2009, as the bank was preparing to repay $10 billion of government aid received in the credit crisis and U.S. lawmakers were overhauling regulation of financial firms. A year later, Goldman Sachs agreed to pay $550 million to settle SEC claims over sales of a mortgage- related security and began reviewing its business standards.

“They have established their game plan and have taken a good look at their business practices, which I helped them with, and now that project is over,” Levitt said today in a telephone interview.

Levitt, the longest-serving SEC chairman, often publicly defended the New York-based firm, saying in 2009 the idea that Goldman Sachs was less ethical than it had been in the past was a “fiction.” The next year, he said many practices in sales of mortgage bonds were industry problems not specific to the company.

Still, he also said Goldman Sachs wasn’t transparent in its dealings with customers before the financial crisis and said the firm should stop promoting itself as putting “customers first” because the slogan ignored tensions inherent in trading.

Levitt is a member of the board of Bloomberg LP, the parent of Bloomberg News, and serves as a senior adviser to Promontory Financial Group LLC. BitPay and Vaurum, two bitcoin companies, announced this week that Levitt will advise them. He was a senior adviser to private-equity firm Carlyle Group LP until last year.