Aintree racecourse is looking for a new sponsor for the Grand National after John Smith's confirmed it would not be renewing its deal beyond the 2013 race.
The ale company, which has backed the race since 2005, will continue to be involved with racing at other tracks.
"With the ex-course boss Julian Thick out after the re-structuring of Aintree's parent company, and the British Horseracing Authority's articulate top vet leaving too, this news just adds to the difficulties facing the home of the Grand National.
"It looks like John Smith's has made what is a surprising decision mainly for commercial reasons, though the public image of the race - in which two horses have died in both of the last two runnings - must have been in the brewer's thinking as well.
"With that in mind, it remains to be seen how easy finding a replacement turns out to be."
John Smith's Karen Crowley said: "The Grand National has been one of the jewels in our sponsorship crown and the decision was difficult to make."
The 2013 Grand National meeting takes place from 4-6 April.
The race was first staged at the Liverpool racecourse in 1839 and has developed into one of the most famous chases in the world with fences like the Chair, Becher's Brook, Valentine's and the Canal Turn known around the globe.
Aintree chairman Lord Daresbury is confident that the high profile of the race will mean that a new sponsor should not be too hard to find.
"I am completely confident the race will attract plenty of new interest," he told the Times.
Neptune Collonges won a dramatic 2012 race
in a photo-finish with Sunnyhillboy.
However, two horses, Cheltenham Gold Cup winner Synchronised and According to Pete
suffered fractured legs in the race and were later put down.