DALLAS • United Airlines has joined Delta Air Lines in banning big-game trophies as freight after the killing of Cecil the lion in Zimbabwe triggered mounting global outrage.

"We felt it made sense to do so," Mr Charles Hobart, a United spokesman, said on Monday in disclosing the carrier's decision to prohibit transportation of elephants, rhinoceroses, leopards and water buffaloes as well as lions. Hours earlier, Delta announced its new policy covering the same five animals.

The carriers spotlighted the logistics that follow a visiting hunter's bagging of African wildlife: getting the head, horns or hide back home.

Airlines already faced animal rights groups' pressure to reject such cargo even before last month's killing of Cecil, 13, a star attraction for tourists at Zimbabwe's Hwange National Park. Neither United nor Delta referred to Cecil, which was allegedly lured out of the park.

The wildlife authorities in Zim-babwe have suspended hunting of lions, leopards and elephants in some areas near the park amid conflicting reports on whether poachers had killed another lion, possibly Cecil's brother.

"Prior to this ban, Delta's strict acceptance policy called for absolute compliance with all government regulations regarding protected species," the Atlanta-based airline said. "Delta will also review acceptance policies on other hunting trophies with appropriate government agencies and other organisations supporting legal shipments."

Delta is the biggest US carrier to Africa, while United serves only Lagos, Nigeria, on the continent.

Zimbabwe has requested the extradition of Dr Walter Palmer, the Minnesota dentist who shot Cecil. Professional hunter Theo Bronk-horst, who assisted in stalking the animal, has appeared in court in the country.

BLOOMBERG