LONDON, May 26 (Reuters) - The first woman to chair Oxford University's poetry department announced she was stepping down on Tuesday following allegations that she was involved in a campaign to discredit a rival for the post.

Ruth Padel, an award-winning poet who has taught at both Oxford and Cambridge, was elected Oxford's professor of poetry just 10 days ago after her chief rival, 1992 Nobel literature laureate Derek Walcott, pulled out.

Walcott, a West Indian born poet, withdrew after a dossier laying out sexual harassment allegations made by a student he taught at Harvard University more than 25 years ago was posted anonymously to a group of Oxford academics.

In a statement issued earlier this month he described it as a "low and degrading attempt at character assassination".

Padel, 63, denied having anything to do with the mailings but admitted having contact with journalists about Walcott.

She was due to hold a press conference on Tuesday morning to announce her resignation, but ahead of that announcement newspapers published excerpts from her resignation statement.

In it she denies taking part in any smear campaign against Walcott, 79, but said she regretted having shared information about him with journalists.

"I naively - and with hindsight unwisely - passed on to two journalists, whom I believed to be covering the whole election responsibly, information that was already in the public domain," the BBC quoted the statement as saying.

"I wish to do what is best for the university and I understand that opinion there is divided. I therefore resign from the Chair of Poetry. I hope wounds will now heal and I wish the next professor all the best."

Oxford's chair of poetry dates back to 1708 and has been filled by many eminent poets over the years, including Seamus Heaney, W.H. Auden and Matthew Arnold.

(Reporting by Luke Baker; Editing by Jon Boyle)