Former GOP mayoral candidate Paul Massey is returning to his real estate brokerage career by launching a new company called B6 Real Estate Advisors.

“We love the ‘Building by Building, Block by Block’ tagline,” he said of the new moniker.

B6 will specialize in middle-market investment sales ranging from $1 million to $200 million, along with capital market offerings.

While he “loved” running for office, Massey said, “I did a big exploration of what I wanted to do to be happy. And I kept coming back to this — sales, leasing.” And he is adding mortgages to the offerings.

“The new aspect is that we will have the third leg, which will be the fully integrated capital markets,” he explained.

Now working out of 275 Madison Ave. with about 20 people, Massey is officially launching July 1 in Manhattan and New Jersey and intends to open offices in both Brooklyn and Queens. He is also inches away from leasing new Manhattan digs through Bill Montana of Savills Studley.

“It’s great space in a great building and location for recruiting,” Montana said.

Massey will also use the territory model perfected by his previous firm, Massey Knakal Realty Services. “We were the authority on the ground with boots on the ground,” he said of the investment sales firm. “I intend to do that, but also bring transparency to the debt market with [information on] who’s lending on what terms. We brought clarity to what properties were worth and now we will bring clarity to what money will cost you.”

Debt offerings will help buyers complete their purchases, while those property owners who don’t want to sell can work with dedicated B6 capital markets professionals to refinance.

“In our model, people specializing in debt will only do debt, and sales will only do sales,” he explained.

The intent is to go after market share through a collaborative office plus a proprietary technology and data platform.

Additionally, former Massey Knakal colleagues Neil Heilberg and Michael Wlody are joining as COO and CFO, respectively.

Wlody had been treasurer of Massey’s mayoral campaign, which had been blessed by Cushman & Wakefield — to which Massey and partner Bob Knakal sold Massey Knakal Realty Services for $100 million at the end of 2014.

Knakal remained chairman of the company’s city investment sales until last week, when he was terminated just days before the end of his contract.

Both Knakal and Massey are coy about Knakal’s next steps, as he was being courted by several firms.

Meantime, Massey has hired the executive recruiters at Spencer Stuart to search for both a head of recruiting and a head of the capital advisory division.

“People are getting a kick out of it, and I’m getting a positive reception in the marketplace,” Massey said of B6. When he officially opens for business, Massey added, “it will be interesting to see who shows up.”