Sir Alex Ferguson approached Pep Guardiola about Man Utd job in 2012

Sir Alex Ferguson first approached Pep Guardiola about succeeding him as Manchester United manager before finally settling on David Moyes, the club legend wrote in a new book.

In his new publication "Leading," to be published on Tuesday, Ferguson says he met with Guardiola before his final season as United boss began in 2012.

At that point, Guardiola was starting a year-long sabbatical after leaving Barcelona. And despite Ferguson's entreaties, he decided to sign on at Bayern Munich the following summer.

"I had dinner with Pep Guardiola in New York in 2012, but couldn't make him any direct proposal because retirement was not on my agenda at that point," Ferguson wrote.

"He had already won an enviable number of trophies with Barcelona... and I admired him greatly. I asked Pep to phone me before he accepted an offer from another club, but he didn't and wound up joining Bayern Munich in July 2013."

Ferguson retired after the 2012-13 season and admitted the handover to Moyes, who was sacked less than a year into a six-year contract, could have been handled more cleanly.

"I understand why critics, particularly in light of the 2013-14 season, say we should have handled the transition better," Ferguson said.

The 73-year-old insists he was never tempted to return to the dugout following Moyes' dismissal.

"There were some who wanted me to return to the sidelines. But I was not tempted," he said.

Ferguson's first encounter with Moyes in 1998 when he interviewed him for the assistant manager's job at Old Trafford did not end well for the then Preston boss, who was overlooked and Steve McClaren took the position instead.

Moyes, Ferguson writes, was "very tense" during his interview with him following Brian Kidd's departure from United to Blackburn.

"Steve McClaren was the opposite of David," Ferguson added. "He was bright, breezy, and enthusiastic.

"At that point Steve had a lot more experience in the top flight of football than David and that swung my decision."

Ferguson says he looked at Guardiola, Jurgen Klopp, Carlo Ancelotti, Louis van Gaal and Jose Mourinho -- "a spectacular manager" -- as potential successors, but they had all committed to other projects by the time the Scot had decided to retire.

Ferguson insists he always gave Moyes his support following his appointment, and is fully behind current boss Van Gaal.

"I just wanted David and United to win -- just as I do these days with Louis van Gaal," said Ferguson, who claimed TV cameras are now trained on him in the directors box at every United match.

"I think they hoped they would catch me acting like Statler or Waldorf, the two curmudgeons in the Muppets who are always criticising what is happening on the stage."

The man who Van Gaal has anointed as his successor, Ryan Giggs, gets a glowing reference from Ferguson in the book.

"Ryan Giggs is eventually going to be a great manager -- he has intelligence, presence and knowledge," said Ferguson, who describes Giggs, Paul Scholes, Eric Cantona and Cristiano Ronaldo as the only four truly world-class players he managed at United.

Information from Press Association was used in this report.