The Nerazzurri have been tracking the former Chelsea and Everton forward throughout the summer but had been unable to convince Manchester United with a series of offers.
Meanwhile, Lukaku appeared set for Juventus in a part-exchange with Paulo Dybala, only for the Argentine’s demands to lead to the move breaking down.
However, La Gazzetta dello Sport report that a breakthrough has been found and Inter have €65 million offer accepted, with a further €10m agreed in bonuses.
Such was the Nerazzurri’s determination to land Lukaku this summer, a five-year contract has already been drawn up and agreed which will see the Belgian earn €9m per season.
Lukaku is expected in Milan on Wednesday evening and will undergo a medical on Thursday ahead of an official announcement from the Serie A outfit.
The 26-year-old has irked Manchester United this week after failing to report to training, instead returning to former club Anderlecht to keep up his fitness. The powerful striker has scored 42 goals in 96 games since joining from Everton in an €85m switch in 2017.