Frank rebukes House staffer

"When Mr. Roberson was hired, it never occurred to me that he would jump so quickly from the committee staff to an industry that was being affected by the committee's legislation," Frank said in a statement.

Intercontinental had no comment other than to confirm that Roberson began working as the company's vice president of government relations in February, said spokesman Lee Underwood.

Roberson worked on the House regulatory overhaul bill, which would require trades of credit default swaps to be more transparent and traded on clearinghouses, such as the one owned by Intercontinental.

The murkiness and unregulated nature of credit default swaps contributed to a massive taxpayer bailout of American International Group (AIG, Fortune 500), which sold swaps to many Wall Street firms and banks. Exchange companies like Intercontinental eagerly await new rules requiring trades to be made on clearinghouses, and each wants to be the top go-to place for the service.

Federal law prevents Roberson from talking with House staffers on the House Financial Services panel for a year. But he's free to lobby the Senate staffers, who are in the midst of crafting similar overhaul legislation before a final Senate vote.

In Washington, it's common for congressional staffers to leave the federal government for better pay and better hours at companies that seek to influence legislation. Many lobbyists now working for banks, credit unions and derivative companies once worked for lawmakers crafting legislation.

What is unusual is Frank's public rebuke of a move.

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Frank said that when he heard Roberson was in talks with the exchange firm, he removed the staffer from payroll. Frank also banned committee staff from having any contact with Roberson as long as he is the chairman of that panel. That punishment goes beyond the regular one-year ban.

"Fortunately, examples of staff members doing what Mr. Roberson has done are rare," Frank said in a statement. "But even one example is far too much and that is why I wanted to make clear I share the unhappiness of people at this."

Roberson appears to be the first in-house lobbyist for Intercontinental, which paid lobbying firms some $690,000 to lobby Congress on regulatory overhaul in 2009, according to the Center for Responsive Politics.

CNN's Jessica Yellin contributed to this report.  

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