(Reuters) - A gauge of manufacturing activity in the U.S. Upper Midwest rose in April, bolstered by increases in stronger production and hiring activities, according to a private-sector survey released on Tuesday.

Marquette University and the Institute for Supply Management-Milwaukee said their seasonally adjusted index on manufacturing in the Milwaukee region climbed to 55.04 this month from 50.05 in March.

A reading above 50 indicates regional factory activity is expanding.