BEIJING, July 3  -- China's non-manufacturing purchasing managers' index (PMI) dropped to 55 points in June from a six-month high of 55.5 in May, official data showed on Thursday.

The non-manufacturing PMI, compiled by the National Bureau of Statistics and the China Federation of Logistics and Purchasing (CFLP), tracks activity in sectors including construction, software, aviation, railway transport and real estate.

In spite of the slight drop, the non-manufacturing activity was still at a relatively high level, as the index was still 5 points above the boom-bust line of 50, said the CFLP's deputy chief Cai Jin.

A PMI reading above 50 indicates expansion, while a reading below 50 reflects contraction.

The sub-index for new orders dropped 2 points to 50.7, indicating far less domestic orders than a month earlier, while that for new export order saw the largest decline of 2.5 points to stay at 50.2 in June.

The business outlook index edged down slightly to 60.4 points last month from 60.7 for the previous month, showing weaker confidence of companies in the future prospects of the sector, CFLP data showed.