Former mayoral candidate Paul Massey Jr. has leased office space for the headquarters of his new investment sales and capital advisory firm, B6 Real Estate Advisors.

The Post has learned that Massey signed a lease this week for 12,010 square feet, representing the full eighth floor at 1040 Sixth Ave. on the northwest corner of West 39th Street, near Bryant Park.

Bill Montana of Savills Studley represented B6 Real Estate Advisors in the space search and negotiations for the sublease from DHI Group. “It was fully furnished and equipped,” Montana said.

“It’s fantastic space with great views and outfitted perfectly and everything is up and running and ready to go.”

Billy Cohen of Newmark Knight Frank represented DHI Group in the sublease. The ownership, Skyline Development, consented to the transaction.

Similar spaces rent for around the low-$50s per foot.

“We love the Bryant Park area and think it will be one of the places everyone wants to be,” said Massey, who is recruiting brokers. “We are sitting on the biggest transportation hub, which is important because our people will be all over the city and our offices will be all over the city.”

Massey is launching B6 — which stands for Building by Building, Block by Block — in both New York and New Jersey.

The bright space has an open floor plan that Massey believes will enhance a “collegial, collaborative, connected and technology-forward culture.”

He and Bob Knakal grew Massey Knakal Realty Services into a city powerhouse focused on investment sales before selling to Cushman & Wakefield in 2015. Massey campaigned as the GOP candidate for mayor before dropping out of the race.