Former Federal Reserve Chairman Paul Volcker reportedly doesn’t approve of changes made in the rule named after him in the financial reform bill.

The Volcker rule was originally slated to completely forbid banks from running private equity and hedge funds. But banks lobbied hard against the measure, and they had the support of some members of the Obama administration and Congress. So legislators changed the bill to allow banks to invest as much as 3 percent of their capital in such funds.

Volcker, an adviser to President Barack Obama, didn’t anticipate the change, knowledgeable sources tell Bloomberg.

“The Volcker rule started out as a hard-and-fast rule on risky trades and investments,” Anthony Sanders, a finance professor at George Mason University, told Bloomberg.

“But through negotiations, it was weakened and ended up with many loopholes.”

Banks may be given up to 12 years to trim their positions in private equity and hedge funds, lawyers told Bloomberg.

Volcker didn’t express any disappointment in public, saying in a statement that the latest version of the bill “provides a constructive legal framework for reform of the financial system.”

Ace banking analyst Dick Bove doesn’t see the bill doing much to restrain banks.

"This is a populist surge of activity to say 'hey, we'll get these bad guys on Wall Street that did bad things to you,'" he told CNBC.

But banks will find a way around the restrictions, he says.