Manchester United made a longawaited breakthrough last night in their bid to sign Zoran Tosic and Adem Ljajic, the two Serbian youngsters, in a combined £16.3 million deal from Partizan Belgrade.

The move was thrown into doubt last month because of Tosic’s wage demands and the number of agents trying to get involved in the transfer, prompting reports that Arsenal or Manchester City could hijack the deal. But it emerged last night that, after another day of negotiations, those potential snags have been overcome and that, barring a last-minute hitch, the joint move will be announced in the coming days.

Tosic, a 21-year-old winger, is expected to move to Old Trafford immediately, having been granted a work permit, although the timing of Ljajic’s arrival is less clear, given that the midfield player, 17, may benefit from spending the remainder of the season with Partizan.

Sir Alex Ferguson, the United manager, who made a personal plea on Tosic’s behalf at his work-permit hearing in Sheffield, regards the pair as players of outstanding potential, with Tosic, a full international, regarded as a potential long-term successor to Ryan Giggs. Under the terms of the deal, United have agreed to pay Partizan a maximum of £16.3 million if the players meet certain pre-identified targets, but the up-front payments will be considerably smaller.

Tosic and Ljajic are likely to be United’s only acquisitions during the transfer window, with the future of Carlos Tévez unlikely to be resolved until the summer. The Argentina striker’s two-year loan agreement at Old Trafford expires at the end of the season, but, while United had hoped to secure the permanent signing of the forward before Christmas, the situation appears likely to drag on.

Although Tévez has expressed concerns to Ferguson at being used primarily as back-up for Wayne Rooney and Dimitar Berbatov, he is thought to view his long-term future as being at Old Trafford, despite interest in the player from Arsenal, Inter Milan and Real Madrid. David Gill, the United chief executive, has held a series of discussions with Kia Joorabchian, the businessman who owns the player’s economic rights, but a deal has yet to be concluded.

United are understood to have paid between £6 million and £10 million to secure Tévez on loan, with those costs expected to be included in a final fee that has been forecast to exceed £30 million. With Tévez not guaranteed a starting position in Ferguson’s first-choice XI this season, United would prefer to be able to negotiate the price, although there is the possibility that their hand could be forced by rival interest.

Cristiano Ronaldo, meanwhile, has moved to assure United’s supporters that there is no truth in the latest reports that he is to join Real at the end of the season. An official from the Spanish club claimed last month that a deal has been agreed to sign the United forward, but Ronaldo said: “Whoever says that is a liar because I am happy at this club, I want to stay here and I feel at home here.”

This is perhaps Ronaldo’s most encouraging statement about his future in months, although it was made in an interview with MUTV, United’s television station, which on numerous occasions last May he told that he was “happy”, while telling the rest of the world that he dreamt of playing for the Spanish champions.