Package carriers DHL and FedEx raised their fuel surcharges for both air and ground services in May as fuel prices rose significantly.

Effective April 30 through June 3, the new rate for DHL Air Express and international freight is 14.5 percent, up from 14 percent in April. For ground delivery services, the new rate is 3.8 percent, up from 3.5 percent in April.

DHL's fuel surcharge is based upon the spot price for fuel published monthly by the U.S. Department of Energy. The method closely links fuel surcharges to current fuel prices and adjusts quickly to changes up or down in fuel prices.

FedEx raised its fuel surcharges effective May 1 through June 4. The FedEx Express fuel surcharge for U.S., U.S. outbound and Puerto Rico express services is now 13.5 percent, up from 12 percent in April. The fuel surcharge rate for both U.S. and international shipments of FedEx Ground services is 3.75 percent, up from 3.5 percent in April.

The FedEx Express fuel surcharge is subject to monthly adjustment based on a rounded average of the U.S. Gulf Coast spot price for a gallon of kerosene-type jet fuel. The FedEx Express fuel surcharge for IXF and ATA services is based on chargeable weight. The surcharge percentage for FedEx Ground services is subject to monthly adjustment based on a rounded average of the national U.S. on-highway average price for a gallon of diesel fuel.