"Following discussion between the Police, the Premier League, Trafford Council and the clubs, our match against Liverpool has been postponed due to safety and security considerations around the protest today," United said in a statement after the game was called off.
"Discussions will now take place with the Premier League on a revised date for the fixture."
An hour after the scheduled 1530 GMT kickoff, both sets of players were still in their hotels. The Lowry Hotel, where United's players were preparing for the match, was also the scene of a large anti-Glazer protest.
