The Argentine forward has joined the Rossoneri, a development which appears to confirm that the Italian champions have finally given up on signing Carlos Tevez
The Italian champions have long had an agreement in place to sign Lopez but even after the player had met with CEO Adriano Galliani on Friday it was still unclear if the deal would go through because of the club's continued attempts to land Manchester City striker Tevez.
However, Galliani maintained that the situation would be resolved by 19.00CET and shortly after that deadline, Milan Channel revealed that the club had registered Lopez as a Rossoneri player.
It has not yet been confirmed if Milan have abandoned their pursuit of Tevez and it was reported by both Sky Sport Italia and La Gazzetta dello Sport less than a couple of hours before the Lopez announcement that Galliani had made a last-ditch plea to City chairman Khaldoon Al Mubarak to allow the former Corinthians striker to leave.
Milan had appeared near-certainties to land Tevez during the current transfer window having already agreed terms with the player, who, according to Galliani, only wanted to join the Rossoneri in spite of interest from Inter and Paris Saint-Germain.
However, they seemingly ended their pursuit of the player following Alexandre Pato's decision to turn down a move to PSG earlier in January.
But Inter then had a bid rejected for Tevez, while PSG broke off negotiations five days ago and Milan then re-entered the race.
The 27-year-old forward has not played for City since refusing to come on as a substitute in the English outfit's Champions League loss to Bayern Munich at the Allianz Arena earlier this season.