Manchester United have held talks with representatives of former Chelsea manager Jose Mourinho.

The 53-year-old Portuguese, who was sacked by the Blues in December, is increasingly hopeful of succeeding Louis van Gaal at Old Trafford.

No agreement has been reached, and the club have made no comment, but negotiations have begun.

Dutchman Van Gaal, 64, is expected to leave United at the end of the season - one year earlier than scheduled.

That would leave the way clear for Mourinho, who is known to be excited by the prospect of taking over at Old Trafford.

The United hierarchy are thought to be keen to respond after Manchester City secured the services of coveted former Barcelona coach Pep Guardiola earlier this week.

Mourinho's arrival would mean a resumption of a rivalry that began in Spain when he was coach of Real Madrid between 2010 and 2013.

It is widely assumed the most obvious alternative to Mourinho is Ryan Giggs, Van Gaal's assistant.

The Welshman, who joined United aged 14, made a record 963 appearances for the club and won 13 Premier League titles.

The 42-year-old took over as manager on an interim basis in April 2014 following the sacking of David Moyes.

Although he has not spoken about the United job since Van Gaal took over, it would be a surprise were he not interested in replacing the Dutchman should the opportunity arise.

However, while Giggs was happy to further his education under Van Gaal, he is unlikely to be as willing to work with Mourinho.

Twice in recent weeks, Van Gaal's tenure has seemed perilous.

However, defeats by Stoke on Boxing Day and Southampton on 23 January have been followed by an improvement in both form and performance.

United, who are five points adrift of the Champions League places, play Chelsea on Sunday (16:00 GMT).