HOUSTON, Jan. 24 (Xinhua) -- U.S. manufacturers reported strong start to 2018, but service sector growth eased again, according to IHS Markit's Purchasing Managers' Index (PMI) on Wednesday.

The latest survey showed that U.S. manufacturers reported a strong start to 2018, with production volumes and incoming new work both rising at faster rates than seen at the end of last year. At the same time, export sales expanded to the largest degree since August 2016.

More favourable demand conditions encouraged another robust rise in employment numbers, although the rate of job creation eased slightly from December's 39-month peak.

Adjusted for seasonal influences the headline HIS Markit Flash U.S. Manufacturing Purchasing Managers' Index (PMI) rose to 55.5 in January, from 55.1 in December. The latest reading pointed to the sharpest improvement in manufacturing business conditions since March 2015.

Meanwhile, the January data indicated another solid expansion of U.S. private sector business activity, underpinned by the fastest rise in new work for five months. Manufacturing production continued to increase at a much faster pace than service sector activity.

At 53.8 in January, down from 54.1 in December, the seasonally adjusted IHS Markit Flash U.S. Composite PMI Output Index signaled the least marked rate of business activity expansion since May 2017. Nonetheless, the headline index has now posted above the 50.0 no-change threshold for 23 consecutive months.

Slower private sector output growth reflected the weakest rise in services activity for nine months. In contrast, manufacturers experienced one of the strongest rates of production growth since the first quarter of 2015, supported by improving domestic sales and sustained inventory building in January.

The seasonally adjusted IHS Markit Flash U.S. Services PMI Business Activity Index registered 53.3 in January, down slightly from 53.7 in December, to signal the slowest rise in service sector output since April 2017.

Despite weaker business activity growth, the latest data revealed a robust and accelerated upturn in new work received by service providers. Meanwhile, service sector business confidence picked up to its strongest for three months in January.

January data pointed to a solid increase in staffing numbers across the service economy, which survey respondents linked to long-term expansion plans and improved business confidence. That said, the rate of job creation eased slightly since December and was the least marked for seven months.

Chris Williamson, chief business economist at HIS Markit, said: "January saw an encouraging start to the year for the U.S. economy. Business activity across the manufacturing and service sectors continued to expand, driving further job gains as companies expanded capacity," adding that manufacturing is faring especially well, in part thanks to the weaker dollar, providing an important spur to the economy at the start of the year.