Origi will be out of contract at the end of next month and he is set to leave Liverpool on a free transfer.
Liverpool had an option to extend his contract if the Belgian had made ten appearances in the Premier League, but that is no longer possible as he has only featured in seven matches, with two games left in the Premier League for the Reds.
Once it became clear that the Reds would not be able to extend his contract, AC Milan made the negotiations with Origi official with the Merseyside giants.
According to Italian daily Tuttosport, the Rossoneri sent an email to Liverpool and told them about the negotiations with the Belgian.
AC Milan made their intention to sign the forward on a free transfer known to the Premier League giants.
Negotiations are ongoing between AC Milan and the representatives and Origi is expected to sign a four-year contract worth €3.5m per season.
Origi is tipped to undergo a medical with AC Milan after the Champions League final later this month.
