CHICAGO — The Mayo Clinic is announcing an affiliation with the Chicago-area’s NorthShore University HealthSystem.

The multi-year agreement will give NorthShore patients quick access to Mayo specialists and research in cardiovascular, cancer and neurological cases.

NorthShore will pay the Rochester-based Mayo Clinic an undisclosed annual fee under the deal, which begins Oct. 1.

The nonprofit NorthShore operates four hospitals in Chicago’s northern suburbs.

Mayo Clinic President and Chief Executive Dr. John Noseworthy said it’s important for Mayo to have a strong presence in Chicago.

The affiliation is the ninth for the Mayo Clinic, a renowned medical facility that has treated foreign heads of state and royalty.