A rising yuan will not cause heavy losses to China's 3-trillion-U.S. dollar foreign exchange reserves, the nation's forex regulator said on Friday, refuting media reports that a stronger yuan against the U.S. dollar had led to heavy losses of the huge forex reserves.

Investment returns of China's forex reserves have maintained steady for years, the State Administration of Foreign Exchange (SAFE) said in a statement on its website, in response to some experts' view that a stronger yuan against the U.S. dollar had caused a loss of 271.1 billion U.S. dollars since 2003.

"The ratio of our returns is much higher than the inflation rates in the United States, European Union and Japan where the reserves are invested, which boosted the real purchasing power of the reserves," SAFE said.

The annual growth of the Consumer Price Index (CPI), a main gauge of inflation, was 2.4 percent in the United States and 2.1 percent in the European Union during 2000 and 2010. In Japan, inflation dropped 0.2 percent per year.

SAFE noted the forex changes could only be reflected in the book value of the reserves, not in the real value. A change in the real value will occur when the reserves assets are exchanged for yuan. But China does not have to do that on a large scale.

As China's forex reserves are denominated by the U.S. dollar, a weaker dollar boosts the book value of the assets.

SAFE also contended the book value loss of the forex reserves from a rising yuan are much less than the book gains of the nation's overall financial assets which are denominated by the U.S. dollar.

China has accumulated the world's largest forex reserve of 3.04 trillion U.S. dollars by the end of March due to its booming exports over the past decade.

The massive stockpile has fed China's growing needs for forex, but also added inflation concerns as the People's Bank of China (PBOC), the central bank, has to print the same amount of yuan to offset the forex inflow.

Yi Gang, deputy governor of the PBOC, has said management of the massive forex reserves is getting more challenging.