--FILE--A pedestrian walks past the headquarters and head office of the People's Bank of China (PBOC), China's central bank, in Beijing, China, 17 June 2015. The People's Bank of China announced Friday (11 December 2015) that the yuan would be freely convertible for corporations registered in three Chinese free-trade zones in Guangdong, Tianjin and Fujian - albeit with conditions attached that have some analysts criticising the move as not going far enough. The key change comes at a time when the yuan has touched four-year lows. The onshore yuan ended down 175 basis points on Friday, or 6.4553 against the dollar, while the offshore yuan touched 6.5322. The central bank attached two key qualifications for the opening: corporations should not be engaged in certain sensitive industries on a government "negative list", and the convertibility will be subject to an annual limit of US$10 million.