The Federal Deposit Insurance Corp on Tuesday voted to approve a five-agency revision of the post-crisis regulation known as the Volcker Rule.

The tweak, if sanctioned by all regulators, would help clarify the way in which banks trade securities using their own funds, the ban of which was a key portion of legislation from the post-financial crisis bank crackdown.

That issue concerns the definition of "proprietary trading," a transaction conducted by a firm designed for direct market gain instead of investing on behalf of clients.

The regulators hope to clarify the definition of proprietary trading and adjust the ban that prohibits banks from making short-term investments with their own capital. The move comes in response to industry complaints that the rules are too convoluted and burdensome.

"One of the post-crisis reforms that has been most challenging for implement for regulators and industry is the Volcker Rule, which restricts banks from engagement in proprietary trading and from owning hedge funds and private equity funds," said Jelena McWilliams, chairman of the FDIC.

"In fact, the rule has turned out to be so complex that it required 21 sets of Frequently Asked Questions, or FAQs, issued by the regulators within three years of its adoption," she added.