Following a detailed review and assessment of clubs wishing to participate in the top two levels of women's football in England, the FA revealed that 11 teams would contest the top-flight Women's Super League for 2018-19, while 12 teams will make up the Women's Championship.
United have been criticised for not reviving their scrapped women's team from 2005 while the game has shown significant growth, particularly with rivals Manchester City becoming part of City Football Group in 2012 and winning several trophies.
The FA's head of women's football, Sue Campbell, said tough decisions had to be made but the announcement was a milestone in the sport's history.
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"Such is the strength of women's football in this country, there have been some difficult decisions to make but they've been made with the sport's best interests at heart," Campbell said in a statement.
"This is a hugely exciting time for the game and I am hopeful that we will look back upon this as one of the most significant decisions made in its history."
The news was heralded by United's executive vice chairman Ed Woodward.
"We will be making some exciting announcements in the coming days and weeks," Woodward said in a statement on the club's website. "Starting a professional team from scratch is challenging but rewarding and we will make every effort to provide the support and experience for the new women's team to be successful and to uphold the fine traditions of our great club."
The 2018-19 season will begin on Aug. 18, with the opening round of fixtures being the Continental Tyres Cup, before both leagues get underway on Sept. 8.
The reigning Super League champions are Chelsea FC Women who also won the FA Women's Cup earlier this month.
The 11 clubs which will form the FA Women's Super League for the 2018-19 season are:
Arsenal
Birmingham City Ladies
Brighton & Hove Albion Women
Bristol City Women
Chelsea FC Women
Everton Ladies FC
Liverpool Ladies FC
Manchester City Women
Reading FC Women
Yeovil Town Ladies
West Ham United Ladies*
The 12 clubs which will form The FA Women's Championship for the 2018-2019 season are:
Aston Villa Ladies FC
Doncaster Rovers Belles
Durham Women FC
London Bees
Millwall Lionesses
Sheffield FC Ladies
Tottenham Hotspur Ladies
Charlton Athletic Women**
Leicester City Women*
Lewes FC Women*
Manchester United Women*
Sheffield United Ladies*
*Approved within the open application phase
**Winners of The FA Women's Premier League Championship (third-tier) playoff
(Reporting by Christian Radnedge; Editing by David Holmes)
