The U.S. Securities and Exchange Commission is including options exchanges in its review of controversial flash orders, which give traders an advance look at trading orders, the regulator said on Wednesday.

The stock markets regulator is mulling ways to eliminate flashes, optional services that alert computer trading programs to the intentions of investors. Critics say that flash orders cloud transparent prices and benefit those with advanced trading software.

SEC spokesman John Nester said SEC staff envisions that options exchanges will be included in any proposals to the agency's five commissioners. Any rule making would need the approval of the majority of the commissioners.

The Nasdaq stock market and BATS Exchange both said August 6 that they would voluntarily stop offering flash orders, which last for a fraction of a second before an exchange or alternative venue routes them elsewhere to the best national bid or offer. They had started offering flash orders in June.

(Reporting by Rachelle Younglai and Sinead Carew; Editing by Steve Orlofsky)