The central parity rate of the yuan, China's currency Renminbi (RMB), gained only by 9 basis points Friday but still struck a new record high at 6.7172 per U.S. dollar, according to the data released by the China Foreign Exchange Trading System.

Friday's yuan central parity against U.S. dollar beat the previous record of 6.7181 per U.S. dollar on Thursday, extending the Chinese currency's gains to six consecutive trading days, according to the data released by the China Foreign Exchange Trading System.

The yuan has seen increased volatility in the trading days since the People's Bank of China (PBOC), the central bank, announced on June 19 this year to increase exchange rate flexibility.

This week's strength of the yuan has lifted the Chinese currency's appreciation against the U.S. dollar by 1.6 percent from the rate of 6.8275 per U.S. dollar that was set a day before the PBOC's pledge to increase flexibility.

On China's foreign exchange spot market, the yuan can rise or fall 0.5 percent from the central parity rate during trading each day.

Based on Friday's central parity rates, the yuan's value strengthened against all the currencies within its basket with lower rates except the euro.

The PBOC released the yuan's central parity rates against a basket of currencies -- the U.S. dollar, the euro, the Japanese yen, the Hong Kong dollar, the British pound and the Malaysian Ringgit.

The yuan's parity rate against the euro was set by the central bank at 8.77.54 Friday, higher from Thursday's 8.7285.

The yuan's rate against 100 yen was 7.8348 Friday, lower from 7.8496 Thursday.

The central parity of RMB against the U.S. dollar is based on a weighted average of enquired prices from all market makers before the opening of the market in each business day.

The central parity of RMB against the other five currencies is based on the central rate of RMB against the U.S. dollar of the same business day as well as the exchange rates of the five currencies against the U.S. dollar at 9 a.m. (0100 GMT) of the same business day in the international foreign exchange market.