Spanish utility firm Gas Natural has withdrawn its bid for Endesa firm
Spanish utility firm Gas Natural has withdrawn its bid for Endesa, leaving Germany's E.ON as the only contender.
The firm, which first made an offer in 2005 for 24bn euros, wants compensation because it says E.ON was given more information.
The move comes a day before the deadline for the firms to submit sealed bids. E.ON must now convince Endesa to accept its higher, 37bn euro offer.
The withdrawal by Gas Natural is a turn around after Madrid demanded the right to impose conditions on the takeover, making it seem like Gas Natural's offer was being favoured.
In Gas Natural's withdrawal statement - made in a filing to Spain's market watchdog - the company said it would go to court to seek compensation for damages incurred by the bid.
Some analysts think E.ON will now raise its bid to stop it being thwarted by Acciona, a major shareholder that has opposed the deal.