China's yuan overtook Japan's yen to become the fourth most-used currency for global payments, shrugging off a surprise devaluation to rise to its highest ranking ever and boosting its claim for reserve status.

The proportion of transactions denominated in yuan climbed to a record 2.79 percent in August, from 2.34 percent in July, according to a Society for Worldwide Interbank Financial Telecommunications (SWIFT) statement on Tuesday. It was second for global issuance of letters of credit by value, with a 9.1 percent share, compared with 80.1 percent for the U.S. dollar.

The report comes as the International Monetary Fund (IMF) prepares to conduct a twice-a-decade review of its Special Drawing Rights (SDR) basket, which currently comprises the U.S. dollar, euro, yen and the British pound. China has been pushing the yuan's case for inclusion, which Standard Chartered Plc estimated could trigger as much as $1 trillion of inflows into the currency. The People's Bank of China (PBOC) on Aug. 11 devalued the yuan reference rate by 1.9 percent and switched to a more market-oriented fixing, spurring a 2.6 percent slide in the currency in August.