Racing UK, which manages the media rights for 31 UK racecourses, including Aintree, will feature live prices and interactive betting from Blue Square and eight other leading bookmakers.
The new has been designed to target users of the Racing Post's website, which attracts 35,000 visitors a day, as well as users who are familiar with the internet and may be once-a-year punters, who prefer to have a bet on the race online.
The new site will be streamed live on April 9 to a UK and global audience with video footage featured in the build-up to the big day, including a horse-by-horse form guide, news bulletins and a tipsters' forum in which the Racing Post's experts analyse the chances of each of the runners.
The site is offering sweepstake kits and a competition to win £10,000 in association with Blue Square.
Jeremy Reed, managing director of Trinity Mirror's sports division, said: "This partnership brings together for the first time the extensive information and expertise of the Racing Post and the live and archive video of this great race supplied by Racing UK to create the ultimate Grand National website."
The Grand National website will benefit from promotion across Trinity Mirror's newspapers and online brands and on-air promotion on Racing UK.
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