* Warns of drop in revenue and profit next year
* Posts record revenue for 2018-19
* Woodward says club building for long-term success
* Shares slip 2.6%
* Red Devils Vs Barca graphic tmsnrt.rs/2mSOonP (Adds Ed Woodward comments, detail, background, graphic, shares)
By Shashwat Awasthi
Sept 24 (Reuters) - Manchester United forecast annual revenue would fall for the first time in five years after its failure to qualify for this season's UEFA Champions League but backed manager Ole Gunnar Solskjaer to rebuild the English soccer club.
Executive Vice Chairman Ed Woodward called for patience after the 20-times English champions also forecast a drop in core profit for 2019-20 and said the club was building for long-term success.
"Returning to the roots of our club's ethos of youth-led attacking football is the right way forward," Woodward said on a post-results media call on Tuesday.
United's history is sprinkled with squads built around young talent, most notably under Matt Busby in the 1950s and 1960s and Alex Ferguson's class of 1992, which included the likes of David Beckham and Ryan Giggs.
The team endured a turbulent season in 2018-19 that prompted the departure of manager Jose Mourinho before finishing they finished sixth in the domestic league under former United striker Solskjaer.
"We and the fans demand success and that means winning trophies. That standard has never changed for Manchester United," Woodward said.
"It is important we are patient while Ole and the team build for the future."
The club, which will play in the less lucrative Europa League this season, has made a stuttering start to the new English Premier League campaign and sits eighth in the table after six matches.
Despite a couple of big-money signings to bolster the defence - most notably making English centre-half Harry Maguire the most expensive defender in history - the club has been forced to rely more heavily on its youth system.
United had seven academy graduates in the squad during Sunday's 2-0 defeat against West Ham United.
Woodward, a former investment banker who advised the American Glazer family on its takeover of United in 2005, said the club is reviewing its structure amid increasing calls for the appointment of a technical director to oversee player recruitment and contract negotiations.
Woodward has come under fire as several big-money signings and a trio of managers have underperformed since Ferguson's retirement in 2013, the last time United won the league title.
The club, which has suffered a more than 7% drop in its share price this year, also stands to lose ground to European rivals off the field.
Spanish giant FC Barcelona last week reported here 990 million euros ($1.1 billion) in turnover for 2018-19 and expects to surpass 1 billion euros this year. Domestic rivals Manchester City and Liverpool are also breathing down United's neck.
"Everyone at the club, the board, the manager, the squad and all the staff remain resolute in our desire to get Manchester United back to the top of English football," Woodward said.
Revenue for United's 2019-20 financial year was forecast at between 560 million and 580 million pounds, down from 2018-19's record 627.1 million ($780 million) reported on Tuesday .
The club said Kantar data showed its global fan base had increased to 1.1 billion followers and that it expects 2019-20 core profit of 155 million to 165 million pounds, down from 185.8 million pounds last year.
For the fourth quarter to June 30, revenue rose 8.1% to 131.4 million pounds, while adjusted core profit edged up 2.8% to 10.9 million pounds.
Shares in the company's New York-listed shares were down 2.6% at $16.79 in early trading. ($1 = 0.8036 pounds) ($1 = 0.9096 euros)
Reporting by Shashwat Awasthi, Yadarisa Shabong and Chris Peters in Bengaluru; Editing by Keith Weir and David Goodman