SHANGHAI, May 20 (Reuters) - China"s yuan eased on Thursday as the dollar rebounded on global markets after minutes from the last Federal Reserve policy meeting hinted at the possible tapering of asset sales if the U.S. economic recovery continues apace. Plunges in cryptocurrencies also fueled risk-off sentiment to support the greenback. That sentiment was reinforced by Beijing"s warning on Tuesday against speculative crypto trading, and its decision to ban financial institutions and payment companies from providing services related to cryptocurrency transactions. The firmer dollar pressured the yuan"s official guidance rate and spot prices. Prior to market opening, the People"s Bank of China (PBOC) set the midpoint rate at a one-week low of 6.4464 per dollar, 209 pips or 0.32% weaker than the previous fix of 6.4255. In the spot market, onshore yuan opened at 6.4380 per dollar and was changing hands at 6.4382 at midday, 44 pips weaker than the previous late session close. "Chinese fundamentals are unchanged – real yield differentials have not tilted materially in favour of the RMB, and data prints have not improved significantly either," analysts at OCBC Bank said in a note, expecting the yuan to remain on the weaker side of 6.4 per dollar for the time being. Several currency traders said state-run banks appeared to be buying dollars earlier this week to prevent the yuan from breaching that level too quickly. Zhou Chengjun, head of the financial research institute of the PBOC, recommended that China should free up the yuan exchange rate over time to support wider global adoption of the currency, but his comments had little impact on the market. Separately, China kept its benchmark lending rate for corporate and household loans unchanged for the 13th straight month at its May fixing on Thursday, in line with expectations. "Official goals for reining in credit have already been achieved by other means. As such, we do not expect any changes to policy rates in the coming months," said Julian Evans-Pritchard, senior China economist at Capital Economics. The yuan market at 0401 GMT: ONSHORE SPOT: Item Current Previous Change PBOC midpoint 6.4464 6.4255 -0.32% Spot yuan 6.4382 6.4338 -0.07% Divergence from -0.13% midpoint* Spot change YTD 1.40% Spot change since 2005 28.55% revaluation Key indexes: Item Current Previous Change Thomson 97.36 97.31 0.1 Reuters/HKEX CNH index Dollar index 90.136 90.22 -0.1 *Divergence of the dollar/yuan exchange rate. Negative number indicates that spot yuan is trading stronger than the midpoint. The People"s Bank of China (PBOC) allows the exchange rate to rise or fall 2% from official midpoint rate it sets each morning. OFFSHORE CNH MARKET Instrument Current Difference from onshore Offshore spot yuan 6.4384 0.00% * Offshore 6.6065 -2.42% non-deliverable forwards ** *Premium for offshore spot over onshore **Figure reflects difference from PBOC"s official midpoint, since non-deliverable forwards are settled against the midpoint. . (Reporting by Winni Zhou and Andrew Galbraith; Editing by Simon Cameron-Moore) Our Standards: The Thomson Reuters Trust Principles.