Webber (pictured left) joins from London-based recycling and waste management business First Mile and replaces Nick Moser.
Advantage said Moser had left the consortium after two years to return to Australia with his family.
Webber previously spent 15 years at Thomas Cook in a variety of finance roles across its tour operating and retail division, as well as head of finance at W&O Travel and Regent Holidays.
Julia Lo Bue-Said, Advantage chief executive, said: “I’d like to thank Nick for all he has done for the business during the last two years. We are delighted to have Keith onboard and part of the Advantage team.”