Investors interested in buying portions of the Beth Israel campus are being directed to Douglas Harmon of Eastdil Secured.

The hospital sits on a mid-Manhattan multi-block campus and apartment complex on the westerly side of First Avenue between East 15th and East 18th streets.

While it lies opposite Stuyvesant Town/Peter Cooper Village — which Harmon sold for a record $5.45 billion — the campus is also opposite the leafy and elegant Stuyvesant Square Park, making residential options enticing, especially as StuyTown’s new owner, Blackstone, has plenty of air rights toward seeking landing strip.

Real estate sources say the sale, which is expected to include that full block bordered by First and Second avenues and East 16th to East 17th streets, will also include other First Avenue properties.

It’s unclear whether the landmarked former Stuyvesant High School building at 345 E. 15th St., which is now being used for another school, will be sold. Its modern Bernstein Pavilion, which fronts Second Avenue, will not be sold.

Harmon did not return messages prior to press time.

“Mount Sinai has contracted Eastdil Secured to begin evaluating and overseeing the sale of Gilman Hall, but no other buildings,” a spokeswoman for Mount Sinai Beth Israel said in a statement.

My sources say there is more on the block than Mt. Sinai wants you to think. Stay tuned.