SHANGHAI/SINGAPORE, May 24 (Reuters) - China's yuan weakened to near six-month lows against the dollar on Wednesday, and surrendered all the gains it made this year against a basket of currencies of its trading partners amid fresh signs of tensions in Sino-U.S. relations.

Traders said the yuan was also pressured by strong demand for dollars, but they had not spotted any moves by state banks to slow the pace of the currency's declines.

"The pace of yuan depreciation might be more important now than any particular levels," said a trader at a foreign bank.

On Tuesday, the chair of the U.S. House of Representatives' committee on China, said the U.S. Commerce Department should put trade curbs on Chinese memory chip maker Changxin Memory Technologies (CXMT) after Beijing earlier this week banned the sale of some chips by U.S.-based Micron Technology Inc.

The restrictions by China's cyberspace regulator against Micron are the latest in a widening trade dispute between the world's two largest economies.

Prior to market opening, the People's Bank of China (PBOC) set the midpoint at a near six-month low of 7.0560 per dollar, 234 pips or 0.33% weaker than the previous fix of 7.0326.

Wednesday's fixing was 6 pips firmer than Reuters' estimate of 7.0566. Currency traders said the official guidance was in line with their expectations.

"The absence of push back from policymakers via the daily RMB fix gave the impression that policymakers may be walking the talk in allowing markets to play a greater role in price discovery," said Christopher Wong, FX strategist at OCBC Bank.

"To some extent, these seem to suggest RMB depreciation in an 'orderly manner' may well be within tolerable limits of policymakers."

The weakened midpoint fixing dragged the trade-weighted CFETS yuan basket index down to 98.51, the lowest since Dec. 26, 2022, effectively wiping out year-to-date gains.

In the spot market, the onshore yuan opened at 7.0650 per dollar and weakened to a low of 7.0693 at one point, the weakest since Dec. 1, 2022. It last traded at 7.0618 as of 0258 GMT, 67 pips softer than the previous late session close.

State-run newspaper Economic Daily said in a commentary on Wednesday that the yuan is unlikely to experience sharp volatility as China's economic fundamentals, balance of payments and foreign exchange reserves are generally stable. (Reporting by Winni Zhou and Tom Westbrook; Editing by Jacqueline Wong)