Complex sentence: In July 2014, Adidas and Manchester United agreed a world record $1.29 billion kit deal over 10 years starting from the 2015/2016 Premier League season, the most valuable in sports history, and replacing rival Nike as the club's equipment partner.
Split into simpler sentences: In July 2014, Adidas and Manchester United agreed a world record $1.29 billion kit deal over 10 years, starting from the 2015/2016 Premier League season. This is currently the most valuable kit deal in sports history, and replaced rival Nike as the club's equipment partner.