(Reuters) - Hedge fund Redwheel said in a statement on Sunday that it supported Royal-Mail owner IDS' board decision to unanimously reject a non-binding share bid from EP Group on 11 April.

Redwheel, the third-largest shareholder in IDS, said it was in full agreement with the board that EP Group's offer of 320 pence per share significantly undervalued IDS and its future prospects.

EP Group, owned by Czech billionaire Daniel Kretinsky, made the cash offer on April 9 for Royal Mail.

Kretinsky is working on improving his offer, a source with knowledge of the plans said last week, after his bid was rejected.

(Reporting by Chandni Shah in Bengaluru; Editing by Hugh Lawson)