The office-leasing streak goes on at William Kaufman Organization’s 437 Madison Ave. Three firms have signed new leases at the 850,000- square-foot tower.

Munich American Reassurance Co. has signed for 18,650 square feet, moving from 1177 Sixth Ave. Eos Management took 9,576 square feet. And

law firm Montgomery McCracken Walker & Rhoads is expanding by 7,458 square feet, bringing its total in the building to 35,755 square feet.

The building recently underwent $60 million in capital upgrades.