That figure is reportedly twice what United currently raking in from Nike, who will cease to sponsor the Red Devils at the end of the season. Nike put out a statement last week revealing that "the terms that were on offer for a renewed contract did not represent good value for Nike’s shareholders," though said they were "proud to have partnered with [United] for the last 12 years."
Liverpool's notoriously terrible kit sponsors Warrior and Tottenham Hotspur's Under Armour were both said to be in contention to replace Nike, though Adidas have apparently seen off their American competitors to seal the deal. For kit fans everywhere, that's probably good news.
It's even better news for Louis van Gaal and Ed Woodward, who may well fancy splashing some of the new cash this summer. Please.
Update: confirmed! According to Herbert Hainer, Adidas group CEO:
We are excited to team up with Manchester United, one of the most successful and most loved football clubs globally. Our new partnership with Manchester United clearly underlines our leadership in football and will help us to further strengthen our position in key markets around the world. At the same time, this collaboration marks a milestone for us when it comes to merchandising potential. We expect total sales to reach 1.5 billion GBP during the duration of our partnership.
There's a full statement over on Adidas' website, if you like that sort of thing. Most of the UK press are reporting £750m over ten years. Which is a lot.