Last week, hedge fund Elliott Advisors became the second activist investor to call for Whitbread to split its Premier Inn hotel chain from the Costa Coffee businesses, pushing shares in the company higher.

The Sunday Times reported that Chief Executive Brittain is expected to set out her position on Wednesday. The report said unnamed sources believed she was not "philosophically opposed" to a split, and regarded such a move as a case of "when, not if".

Whitbread declined to comment on the article.

In January, the group said it had an open mind about its future structure.

Whitbread has in recent years sold off its brewing business and some pubs to focus mainly on Costa, as well as Premier Inn hotels, the Beefeater restaurant brand and the Brewers Fayre pub restaurant chain.

Elliott, part of U.S. investor Paul Singer's hedge fund firm, believes splitting Whitbread into two listed entities would allow the market to value it properly, a source told Reuters last week. Fellow activist Sachem Head has also been pushing for a breakup.

(Reporting by William James; Editing by Keith Weir)