It is understood a fee in excess of £1m has been finalised between the clubs, the news coming just 24 hours after Sky Sports reported that Celtic had had a bid of around £900,000 turned down by their Scottish Premiership rivals.
United are due to return for pre-season training on Wednesday and Ciftci is expected to take part – but it remains to be seen if Celtic or any other interested clubs attempt to match Wigan’s bid.
Citfci, who has one year left on his contract, scored 16 goals in 42 appearances for United last term, and has 33 goals in all competitions since signing for the club on a free transfer in 2013.
The Turkish-born Dutchman was a trainee at Portsmouth after signing from ADO Den Haag in 2007 and he made 19 league appearances for Pompey before a move to Turkish club Kayserispor.
Between 2011 and his 2013 move to Scotland, Ciftci barely played – making just 11 appearances in Turkey and then seven in a year-long spell at Dutch club NAC Breda.