Yuan forwards took their biggest tumble in three weeks on speculation that a worsening outlook for exports will dissuade China from allowing its currency to gain value.

The People's Bank of China, the country's central bank, lowered its daily reference rate by 0.22 percent, the most since March 12, to 6.2858 a dollar on Monday.

Export orders at China's Canton Fair dropped 2.3 percent from a year ago, the first decline since 2009, the newspaper China Securities Journal reported on Monday.