The 2016 Grand National at Aintree will start an hour later than in previous years, at 17:15 BST, to give fans a better opportunity to watch the race.
In 2015, 8.9m viewers watched the race on Channel 4, with more than 600m TV viewers tuning in worldwide.
Channel 4's head of TV events Ed Havard said: "The 17.15 slot follows the results round-up on BBC Radio 5 live, providing fans with the opportunity to listen on their journeys home."
The race is on Saturday, 9 April.
Havard added that the move "will place the National as the fitting climax of the three-day festival", which starts on Thursday, 7 April at the Liverpool racecourse.
Head of BBC Radio Sport Richard Burgess said: "We look forward to providing extensive build-up and uninterrupted commentary on BBC Radio 5 Live of the Grand National in its new time slot.
"We'll also have plenty of time for reaction after the race, with our correspondent Cornelius Lysaght leading the BBC team at Aintree."
John Baker, Regional Director of the Jockey Club North West, called it an "extremely positive step forward for the 'People's Race', adding: "This is a positive move for the Crabbie's Grand National and we're excited about the possibility of showcasing the greatest chase in the world to a wider national and global audience."
A handicap hurdle for conditional and amateur jockeys will now be the only race which will follow the National, at 18.10 BST.