LONDON (Reuters) - Flutter shareholders backed a proposal to move the primary listing of its shares from London to New York on Wednesday, just three months after the world's largest online betting company added a secondary listing in the United States.

An increasing number of firms are moving away from European listings in favour of U.S. markets, where valuations can be higher. The fast growing U.S. betting market is now Flutter's largest by revenue and its Fanduel brand is the market leader.

The resolution to move to a primary U.S. listing was backed by 98% of shareholders, according to proxy votes tallied up at the company's annual general meeting. Flutter said in March that it expects the primary listing to become effective on May 31.