BEIJING, Nov 30 (Reuters) - Growth in China's services industry slowed for the second straight month in November, an official survey showed, adding to pressure on the economy amid cooling demand at home and the threat of higher U.S. tariffs.

The official non-manufacturing Purchasing Managers' Index (PMI) released on Friday fell to 53.4 from 53.9 in October, but remained well above the 50-point mark that separates growth from contraction.

The services sector accounts for more than half of China's economy, with rising wages giving Chinese consumers more spending power. But recent data has suggested consumer demand and confidence may be faltering.

The composite PMI, which covers both manufacturing and services activity, slipped to 52.8 in November, from October's 53.1. (Reporting by Beijing Monitoring Desk; Editing by Kim Coghill)