Image copyright Getty Images Image caption The Worlds End, ridden by Adrian Heskin, in a race at Aintree on Friday

A bumper roster of sport including the Grand National, the Masters and Premier League games, is expected to produce a record weekend for bookmakers.

The Grand National will attract about £225m in wagers across the betting industry, William Hill predicted.

Combined with other sporting fixtures it expects to take "the highest turnover levels on any weekend in history", the bookmaker said.

Saturday's race is expected to be seen by 600 million people globally.

"The Grand National is the public's race and we will see millions of once-a-year punters coming in to betting shops or downloading the app," William Hill spokesman Rupert Adams said.

The race is set to attract over 35 million bets with the average being worth £4.41.

Image copyright Getty Images Image caption Jockey David Mullins with Michael O'Leary, owner of Rule The World, which won the 2016 Grand National

William Hill is also hoping for another big-priced winner in the Grand National this year. The last five races have produced winners at odds of 33/1, 25/1, 25/1 and 33/1.

Ryanair chief executive Michael O'Leary owns five of the 40 horses in Saturday's field.

He is hoping to become the first owner to win consecutive Nationals with different horses since 1954 after Rule the World, ridden by David Mullins, claimed victory last year.

Last year, the start time for the Grand National was moved by an hour to 17:15 BST. The decision proved to be a boost for turnover and William Hill expects that trend to continue.

New sponsor

"The experiment of moving the start time really paid off and we expect the Grand National to smash betting records this year," Mr Adams said.

It is the first year that the race has been sponsored by Randox Health, which analyses blood and urine samples to detect and prevent illnesses.

The Northern Ireland-based firm was set up in 1982 by Dr Peter FitzGerald - a keen horse racing fan.

Meanwhile, the meeting at Aintree could be affected by a 24-hour strike involving members of the Rail, Maritime and Transport union (RMT) at Merseyrail and Arriva Trains North.

Tens of thousands of people travel by train from central Liverpool to the racecourse.

Jan Chaudhry-van der Velde, managing director Merseyrail, said the operator had devised a timetable aimed at transporting as many passengers as normal on Grand National day.

Andy Bell, from Bookies.com, said: "This is a bumper weekend of betting and the Grand National is often the event that sees people have a flutter for the very first time. The new start time means people are back from their Saturday shopping and activities and it is effectively the start of their Saturday evening festivities. It's perfect timing."