NEW YORK (REUTERS) - US manufacturing activity slowed for a second straight month in April, though the rate of growth remained strong, an industry report showed on Thursday.

Financial data firm Markit said its final US Manufacturing Purchasing Managers Index was 55.4 in April, down slightly from 55.5 in March.

Readings above 50 indicate expansion in the sector.

While the index remained below February's level, which had been the highest since May 2010, it was comfortably ahead of January's 53.7 reading, suggesting the effects of a harsh winter have started to fade.

The employment sub-index fell from to 53.7 from 53.9 in March, the lowest in three month, Markit said, though the output component rose to 58.2 from 57.5. The new orders component also rose month-over-month.

"The upturn in manufacturing output and new orders signaled by the survey suggest that the economy should rebound after the disappointing 0.1 per cent annualised GDP growth rate seen in the first three months of the year," said Mr Chris Williamson, Chief Economist at Markit.