U.S. lawmakers will hold a hearing on Sept. 15 to consider whether U.S. government action is needed to address China's exchange rate policy, a key House of Representatives committee said on Thursday.

China loosened its yuan, also known as the renminbi, on June 19 from a 23-month-old peg to the dollar but it has barely risen in value since then.

Many lawmakers believe the currency is undervalued by as much as 25 to 40 percent against the dollar, giving Chinese companies an unfair trade advantage that has caused U.S. manufacturing job losses.

There is no real question that China's deliberately undervalued exchange rate is unfair, contributes to global trade imbalances, and costs the United States jobs and economic growth, particularly in the manufacturing sector, Ways and Means Committee Chairman Sander Levin said in a statement.

We must ensure that China's rhetoric translates into results that are meaningful and that the international trading system ensures fair rules of competition, Levin said.

Congress has for years fumed about the value of the yuan without taking action. However, concern about persistently high U.S. unemployment has put the issue back in the spotlight ahead of congressional elections in November.

Levin said the panel would hear testimony on a proposed bill, the Currency Reform for Fair Trade Act, which would allow companies to ask for countervailing or anti-dumping duties against countries with undervalued currency.

That measure is similar to one pushed by in the Senate by Senator Charles Schumer and several others.

The committee will also probe the idea of the U.S. Trade Representative's office challenging China's currency practices at the World Trade Organization, Levin said.

The hearing notification did not say whether any U.S. Treasury Department or trade officials would testify. (Reporting by Doug Palmer; Editing by Andrew Hay)