Dutch international striker Robin Van Persie completed his move from Arsenal to Manchester United on Friday after signing a four-year deal.
Van Persie, who scored 37 goals for Arsenal last season, is set to make his debut in United's Premier League opener against Everton on Monday.
''Robin is a world-class striker with a proven record in England and in European football,'' United manager Alex Ferguson told the club's website (www.manutd.com).
''His talents need no introduction to our fans - he has scored a number of goals against us in some classic battles with his former club. His movement, finishing and all-round ability are outstanding.''
The 29-year-old, who had also attracted interest from the Premier League champions Manchester City and Juventus, said last month he would not extend his contract at Arsenal. He had one year left on his deal after eight years with the club.
At Old Trafford Van Persie will link up with England striker Wayne Rooney as Ferguson's team try to take the title back from their city rivals.
United have made only one other major signing since the end of last season, Japan midfielder Shinji Kagawa joining from German champions Borussia Dortmund.
Who was the best player at the World Cup?