UPS managed to increase its adjusted diluted earnings per share by 37 percent in the first quarter, driven by growth in the company's international package and supply chain businesses

. Adjusted first quarter earnings were 71 cents a share, up from 52 cents a share from the 2009 quarter.

Revenue gained 7 percent due to an 18 percent boost in international package and 14 percent rise in supply chain and freight, UPS reported.

"We expected the first quarter to be the most challenging of 2010 as the economic recovery gathered steam through the year," said Kurt Kuehn, UPS's chief financial officer. "As it turned out, revenue was stronger than we expected due to international volume gains, increased yields in the U.S. and growth in Forwarding and Logistics. Also, the operating leverage in our streamlined network provided higher margins than anticipated."

In light of the strong performance, the company raised its expectations for 2010 earnings. The company expects full-year adjusted diluted earnings to range from $3.05 to $3.30 per share, up from the $2.70 to $3.05 outlook provided in February.