Sir Stelios Haji-Ioannou, the founder of the budget airline easyJet, has pledged to give £1bn of his fortune to charity.

Haji-Ioannou has signed up to the Giving Pledge, a campaign started by the Microsoft founder Bill Gates and the investor Warren Buffet to persuade wealthy individuals to give away large portions of their wealth to charitable causes.

Haji-Ioannou has promised to donate half of his fortune to his own philanthropic foundation, the Stelios Philanthropic Foundation, which supports scholarships, environmental causes, entrepreneurships and poverty relief in Greece and Cyprus.

The charity operates in the UK, Greece, Cyprus and Monaco, where he lives.

In a statement on the Giving Pledge website, Haji-Ioannou said: “I think all wealthy people have a debt to repay because it is thanks to their customers who bought their goods and/or services that they acquired their fortune.

“It took me another 10 years of both ‘thinking’ and ‘doing’ philanthropy to conclude that by giving more than half of one’s fortune to charity, one can balance the needs of family and friends against other good causes.”

He said he felt that signing up to the Giving Pledge publicly would help to achieve two objectives.

“First, it will keep my foundation and its future trustees disciplined to do good for many generations to come,” he said.

“And second, in the more immediate future I hope that publicising it might inspire others, perhaps those closer to my part of the world, to make the same pledge.”

Haji-Ioannou said that a personal call from Gates helped to persuade him to sign up to the campaign.