Nepal has extended the climbing permits of hundreds of mountaineers forced to abandon Everest after last year's massive earthquake, to try to lure tourists back to the Himalayas, an official said on Tuesday.

Climbers, who paid $11,000 each for a permit last year, quit their expeditions in droves when the April quake triggered an avalanche on Everest base camp that killed 18 people.

The quake marked the second year with almost no summits on Everest after the deaths of 16 Nepali guides in an avalanche in 2014 sparked a shutdown of the world's highest peak.

"The government has decided to extend permits for two years in order to compensate those climbers who could not continue their expeditions due to the earthquake," said tourism department chief Gobinda Bahadur Karki.

Nearly 9,000 people lost their lives when the 7.8-magnitude quake ripped through Nepal, triggering avalanches and landslides that buried part of Everest base camp and destroyed the popular Langtang trekking route.

Following the disaster, Nepal is desperate to revive tourism including its mountaineering industry, key revenue-earners for the impoverished country that is home to eight of the world's 14 peaks over 8,000 metres.

"We hope the number of climbers will increase this year after the government's latest decision," Karki told AFP.

Industry insiders welcomed the move, but said the delay in making the decision had left operators with little time to organise expeditions.

Everest's two-month spring climbing season kicks off in April when weather conditions are deemed ideal for ascents.

"We are not happy that the government decided on this so late. Had the decision come earlier, expedition teams would have a little more time for preparations," said Ang Tshering Sherpa, president of Nepal's mountaineering association.

Kathmandu last year agreed to extend Everest climbing permits until 2019 for foreign mountaineers already holding one, following the 2014 shutdown of the 8,848-metre high peak.