Wall Street's top regulator on Wednesday is set to adopt new rules for pricing stocks at less than a penny, part of a larger package of proposed reforms that could constitute the biggest overhaul of U.

US regulators dumped long-standing penny limits on share trading prices and cut the fees exchanges can charge their users in new equity market rules that nonetheless ended far short of more radical initial plans.

The price increments at which thousands of stocks and ETFs are quoted look set for an overhaul Wednesday, when the US Securities and Exchange Commission votes on final rules to reduce them to less than 1 cent.

Wall Street's top regulator on Wednesday unveiled rules allowing stock markets to price shares in increments of half a penny, rather than the current minimum size of 1 cent, aiming to promote more competitive pricing and reduce investor costs.

Stocks are currently priced in increments of one-cent. But a move by the SEC could lower transaction costs for consumers.

The proposals being considered by the Securities and Exchange Commission are tamer versions of the ambitious revamp of stock trading that Chair Gary Gensler proposed two years ago.

The U.S. Securities and Exchange Commission is poised to approve a rule that will allow exchanges to quote sub-penny prices as it seeks to foster competition, according to a media report. The Regulation NMS: Minimum Pricing is part of a broader set of regulations that proposes to overhaul U.