Manufacturing activity grew for a third straight month in April, but at a slower rate than the previous month, according to the Institute for Supply Management.

The Institute¿s index of business activity dipped to 53.9 in April from a revised 55.6 percent in March. Analysts had been expecting a reading of 55.0.

Because an index over 50 signifies growth in manufacturing, April's figure indicates continued expansion in the sector, although at a slower rate than in March.

¿The overall picture shows growth in manufacturing activity during April and a good beginning for the second quarter," said Norbert J. Ore, chairman of the Institute.