Thursday's midpoint was 318 pips, or 0.47 percent, firmer than previous fix of 6.7343 and was the strongest since July 18, 2018.

But the official guidance rate came in weaker than a Reuters estimate of 6.6984. Several yuan traders also said their models suggested the fixing should have been set firmer than the key 6.7 per dollar levels.

The dollar extended losses after the Fed sent the clearest signal yet that its three-year drive to tighten monetary policy is close to an end in the face of rising pressure on the economy from slowing global growth.