The American Institute of Certified Public Accountants is protesting a provision in a Senate financial-overhaul bill that would give investors an expanded ability to sue people who help commit securities fraud.

In a letter sent Wednesday to the bill's sponsor, Senate Banking Committee Chairman Chris Dodd (D, Conn.), the accounting association says the provision would lower the current legal standard for aiding and abetting cases "from a standard of 'knowingly' committing a violation to mere 'reckless' behavior."

Dodd's bill would permit private civil actions for any person who "knowingly or recklessly provides substantial assistance" to others committing securities fraud.

"Because recklessness is not defined, and as a practical matter is a vague standard, this change alone would result in a significant increase in litigation," the letter says. It was also addressed to the committee's ranking Republican, Richard Shelby of Alabama.

The letter also says the provision in Dodd's bill goes against a 2008 decision by the U.S. Supreme Court that Congress had given the Securities and Exchange Commission the authority to pursue those who aid and abet, but lawmakers specifically hadn't authorized private rights of action.

(By Fawn Johnson, Dow Jones Newswires)