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.

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.

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.

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.