AC Milan and Inter Milan have agreed to work on a shared stadium project, and prefer "complete renovation" of their city-owned San Siro home.
In a statement, Inter Milan says a shared stadium "will serve in the best interests of all stakeholders."
The agreement was announced after talks with Milan mayor Giuseppe Sala about redeveloping land around the 80,000-capacity Giuseppe Meazza Stadium. The clubs have shared it for 71 years.
Italian clubs typically rent publicly owned venues, despite Serie A champion Juventus and rivals in other countries generating more income from owning their stadiums.
Inter's statement says a task force should make progress this year "evaluating several possible options, including a complete renovation of the existing San Siro stadium."