Serbians Zoran Tosic and Adem Ljajic have joined Manchester United from Partizan Belgrade.
Tosic and Ljajic – both attacking midfielders – are United's first signings of the January transfer window.
The club released a statement saying: "United is pleased to announce it has reached an agreement with Partizan Belgrade and the players for Zoran Tosic and Adem Ljajic to join the club.
Tosic, 21, will sign with immediate effect and wear the No 14 shirt, while an agreement is in place for 17-year-old Ljajic to remain with Partizan for the rest of 2009."
Having personally pleaded for the 21-year-old Tosic's work permit at a hearing in November, manager Sir Alex Ferguson had been frustrated that the move was being held up by the Serbia winger's pay demands and number of agents involved in the deal.
There had been fears that Premier League rivals could hijack the move, but the acquisition was completed within 24 hours of the transfer window opening Thursday.
Tosic, who has made 12 international appearances since his debut against Finland in 2007, including at the Beijing Olympics, will join immediately as United looks to close the seven-point gap on Premier League leaders Liverpool with two games in hand.
Ljajic has made just 10 league appearances for Partizan Belgrade since his debut in July, although he underwent a trial at Old Trafford in October when the Serbian club's general manager confirmed Manchester United had been in contact "for some time now".
The 17-year-old right-sided midfielder has been nicknamed "Little Kaka" after impressing in Champions League qualifiers for Partizan Belgrade.
It has been suggested United could end up paying around £17 million for the duo, although that figure is likely to be based heavily on future success and the club have refused to comment on the size of an initial payment.
