China's central bank has raised the value of the yuan against the US dollar by just 0.01%, the national foreign exchange market said, after a devaluation last week rocked markets.

The daily reference rate was set at 6.3969 yuan to the dollar, slightly stronger than Friday's 6.3975, the China Foreign Exchange Trade System said.

The yuan closed at 6.3946 today, stronger than the daily fix but weakening 0.05% from Friday's close of 6.3912.

Chinese authorities keep a tight grip on the currency and it is only allowed to fluctuate by two percent on either side of the reference rate.

Authorities had based the rate on a poll of market-makers, but last week shocked financial markets by suddenly cutting the value of the yuan nearly five percent over a three-day period and moving to what they say is a more market-oriented system.

The mechanism now also takes into account the previous day's close, foreign exchange supply and demand, and the rates of major currencies.