Hard Rock CafÃ© European marketing director Maeve McDonald is understood to have left the themed restaurant chain suddenly.
McDonald, who joined the company about a year ago, was in the middle of conducting customer research with a view to calling an advertising review by Christmas.
She was also planning to organise live performances from up-and-coming bands in the restaurants, which would give them an authentic link with contemporary music.
The Hard Rock chain was the first themed restaurant in the UK, opening in 1971, but in recent years it has come under competitive pressure from other chains such as Planet Hollywood, and a host of other sports bars.
Last year the Rank-owned chain reported a five per cent rise in operating profits on the back of a 40 per cent leap in sales. The company put this under performance down to rebuilding and investment in the brand. Rank bought the chain for 265m in 1996.
A spokesman for Hard Rock CafÃ© refused to confirm that McDonald had left the company.