Eurozone services PMI declined to 51.6 (flash 50.9) from 52.2 in September.
Composite output dropped to 51.9 (flash 51.5) from 52.2, although business activity still grew for the fourth consecutive month.
The fall in the surveys indicate a loss of momentum at the start of Q4, says Markit, raising "concerns that the upturn is faltering" and increasing the pressure on the ECB "to reinvigorate the recovery," especially with inflation so low.
Still, the economy is expanding across the board in Germany, France, Italy and Spain. "Most impressive is the surging pace of growth seen in Ireland."
The euro is +0.2% at $1.3505. (PR)