In another big-ticket private equity firm move, Crestview Advisors has signed for 25,499 square feet on the entire 42nd floor of Minskoff Equities-managed 590 Madison Ave.

Terms weren’t available but a source said the deal was worth 40 percent more than the $100 per square feet that’s the norm for top-floor leases.

Savills Studley’s Mitchell Steir and Greg Taubin repped the tenant. CBRE’s Stephen B. Siegel and Evan Haskell repped the landlord along with Minskoff’s Jeffrey Sussman in-house.