The US service sector expanded for the 46th consecutive month in October with gains accelerating modestly, a business research group said Thursday. The Institute for Supply Management said the Purchasing Managers Index for non-manufacturing businesses -- above the break-even point of 50 for close to four years -- rose from 54.4 in September to 55.4 in October. For more than four years -- for 51 consecutive months -- both the Business Activity/Production Index and the New Orders Index indicated they were in an expansion. In October, however, new orders showed slower expansion than it showed in September with the index down from 59.6 to 56.8. The Activity/Production Index posted a faster gain at 59.7, up from September's 55.1, a gain of 4.6 percentage points. The index measuring new export orders showed growth slowing with the 57.5 mark in September slipping to 53 in October. The index measuring the number of employees rose from 52.7 to 56.2, the institute said. The institute said 10 of 18 service industries reported growth in October, led by management of companies, retail and educational services. Of the eight industries reporting declines, the three sharpest drops were reported by arts, entertainment and recreation; agriculture, forestry, fishing and hunting; and transportation and warehousing.