Wins for favourites generally tend to mean a major hit for bookies taking the action on Britain's biggest horse race of the year and another major firm, Betway, called Tiger Roll's win one of its biggest blows ever.

Shares in London-listed bookmakers were down between 0.8 percent and 1.3 percent by 1152 GMT.

The horse's owner, Ryanair Chief Executive Officer Michael O'Leary, celebrated the second consecutive victory, the first since Red Rum in 1974, by buying drinks for all passengers on his flight home to Dublin, according to footage posted on The Sun's website on Sunday.

Eleven-year-old Tiger Roll, ridden by jockey Davy Russell, had a starting price of 4/1, compared with 14/1 last year https://www.grandnational.org.uk/previous-winners.php.

"When a horse as popular as Tiger Roll wins the UK's most bet on race of the year, it's never going to end well for us," Betway spokesman Alan Alger said on Monday.

"As far as the National is concerned, Tiger Roll's win goes down as one of the biggest blows we have ever suffered."

Others played down the effects on their financials.

"You would think it should be an absolute stinker for us but bizarrely it wasn't that bad a result at all," Betfair spokesman Barry Orr said, adding that bets on places in the race cost the company more. Betfair is part of Ireland's Paddy Power Betfair Plc.

Ladbrokes owner GVC Holdings declined to comment.

(Reporting by Pushkala Aripaka and Tanishaa Nadkar in Bengaluru; editing by Patrick Graham)