United has lost a club record 11 times in the league and 10 times in 22 matches in all competitions in 2014. Worse for Moyes, there has been no discernible improvement in the level of performance, with his chances not helped by the absence of leading striker Robin van Persie for large chunks of the season through injury.
The deposed champions appear ready to spend considerable sums over the summer to strengthen an aging squad. But United's American owners, the Glazer family, were not willing to trust Moyes to oversee such heavy spending.
United is one of the sports world's most lucrative brands — it brought in 363.2 million pounds ($610 million) in revenue last season — but the lack of Champions League action next season will dent income streams.
The Glazers likely would have been concerned that next season's exile from Europe's top club competition may have dragged on for years at a time when player costs are high and interest payments on the club's debts are a real burden. Big United sponsors, such as Nike, may have become restless.
"Clearly Nike and other sponsors are paying for one of the best and most recognized football brands in the world — not one that cannot even make the Champions League," said Louise Cooper, an independent financial analyst in London. "The financials ensured that Moyes was not given the time to perform."
Investors appeared to welcome the news, sending United's share price up 2.1 percent in early New York trading to $18.10.
Such is United's decline that the world's top players are unlikely to want to move to Old Trafford without the pull of the Champions League. With four matches left in the Premier League, qualification for the second-tier Europa League is also looking unlikely.
Giggs has long been regarded as a future United manager, having established himself among United's greats by winning 13 Premier Leagues, four FA Cups, three League Cups, two Champions Leagues, one UEFA Super Cup, an Intercontinental Cup and a Club World Cup as a player.
United denied reports last month that Van Gaal met with a member of the Glazer family, but the Dutchman will be free in the summer. He has the experience of coaching at big clubs that Moyes lacked, having been in charge of Barcelona, Bayern Munich and Ajax in a 23-year managerial career.
AP Sports Writer Rob Harris and Associated Press writer Pan Pylas contributed to this report.
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