SHANGHAI, July 25 (Reuters) - China's yuan weakened slightly against the U.S. dollar on Tuesday, pulled down by a softer official midpoint following a rise in the greenback overnight. Prior to market opening, the People's Bank of China set the midpoint rate at 6.7485 per dollar, 75 pips or 0.1 percent weaker than the previous fix of 6.7410. The move in the yuan guidance, its biggest one-day weakening in percentage terms in three weeks, was mainly due to a rebound in the greenback overnight in the overseas markets on upbeat U.S. economic data, traders said. The dollar index, a gauge that measures dollar strength against six other major currencies, stood at 93.934 at midday, having pulled up from Monday's trough of 93.823, its lowest level since June 2016. The spot market opened at 6.7525 per dollar and was changing hands at 6.7507 at midday, only 5 pips weaker than the previous late session close and 0.03 percent softer than the midpoint. "When dollar index fell, prices of USD/CNY fell; and when dollar index was up, USD/CNY rebounded slightly. Recent intraday trade was mainly following the dollar's movements," said a trader at a Chinese bank in Shanghai. The trader expects the yuan to trade at around the 6.75 per dollar level if the dollar index hovers at 94, and the Chinese currency is likely to test a high of 6.7 if the dollar index weakens again to 92. Several traders said they had not seen major state-owned banks selling dollars in the onshore market on Tuesday morning. The big banks briefly appeared to be dumping dollars on Monday afternoon but were absent for quite a few sessions before that. The Thomson Reuters/HKEX Global CNH index, which tracks the offshore yuan against a basket of currencies on a daily basis, stood at 93.81, firmer than the previous day's 93.74. The offshore yuan was trading 0.05 percent firmer than the onshore spot at 6.7475 per dollar. Offshore one-year non-deliverable forwards contracts (NDFs), considered the best available proxy for forward-looking market expectations of the yuan's value, traded at 6.886, 2.00 percent weaker than the midpoint. One-year NDFs are settled against the midpoint, not the spot rate.
The yuan market at 0348 GMT:
Item Current Previous Change PBOC midpoint 6.7485 6.741 -0.11% Spot yuan 6.7507 6.7502 -0.01% Divergence from 0.03%
Spot change YTD 2.90% Spot change since 2005 22.60%
Item Current Previous Change Thomson 93.81 93.74 0.1
Reuters/HKEX CNH index
Dollar index 93.934 93.977 -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 percent from official midpoint rate it sets each morning.
OFFSHORE CNH MARKET
Instrument Current Difference
Offshore spot yuan 6.7475 0.05% * Offshore 6.886 -2.00%
*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 John Ruwitch)