One of the many concerns expressed on Capitol Hill this week about the Treasury Department’s $700 billion rescue plan was how to keep the Wall Street firms that helped to create the crisis from making a killing if they are hired to help contain it.

William H. Gross, the manager of the country’s largest bond mutual fund, has a solution for that: He is offering to do it free.

“We have a large and brilliant staff that can analyze and has analyzed subprime mortgages that can help the Treasury out,” Mr. Gross, the co-chief investment officer for Pacific Investment Management Company, said Tuesday in an interview at the company’s headquarters here. “And I’d even be willing to say that if the Treasury wanted to use our help, it would come, you know, free and clear as long as every other firm would do the same.”