The Securities and Exchange Commission may let large American companies switch to international accounting rules in six years, a step it says will lower compliance costs and make American firms more competitive.

SEC commissioners yesterday approved a “road map” that might allow corporations with market values exceeding $700 million to abandon American accounting standards by 2014. Under the plan, about 110 U.S. companies that are global leaders in their industries may move to international rules as soon as 2010.

“A global set of high-quality accounting standards would be an international language of disclosure, transparency and comparability,” the chairman of the SEC, Christopher Cox, said at an open meeting in Washington. “It’s a goal worth pursuing.”

Meshing American regulations with rules adopted by other countries is a priority for the agency, which has said companies will be able to reduce expenses by eliminating duplicate accounting. Investors will benefit because they ultimately bear the burden of higher compliance costs, SEC officials argue.

Critics, such as Senator Reed, a Rhode Island Democrat who heads a subcommittee that oversees the SEC, have said the agency may put investors at risk by outsourcing its oversight to less-aggressive regulators.

The SEC’s plan would either require or permit the largest American companies to switch to international rules in six years.

The SEC may either require or permit companies that rank among the 20 biggest in the world within their industry — a group of about 110 corporations — start following international rules in two years. The smallest American companies, those with market values below $75 million, would switch to international rules in 2016.