Sandy Springs-based UPS is ordering three Boeing 767 planes converted from passenger aircraft into freighters.

UPS, which already operates 184 Boeing aircraft, announced the order at the Paris Air Show on Monday.

Boeing said freighter conversions, which it has done for more than 40 years, extend “the economic life of the airplane.”

There's strong demand for 767 freighter conversions due to growth in e-commerce and the express market, according to Boeing.