NEW YORK –  He’s apparently gotten over lamenting that he would have had a better chance as the Republican nominee against New York’s new Mayor Bill de Blasio, who wiped out his GOP opponent, but billionaire businessman John Catsimatidis says even while’s increasing his real estate empire that he hasn’t ruled out running for office again someday.

In an interview with The New York Times, Catsimatidis said, “I’ve known Bill de Blasio for 20 years, and I hope he does a good job. But I love politics; I love people; and if an open seat comes along that I think I would enjoy, I would definitely do it. I want to be in a position to make a difference. I’m keeping my options open.”

That aside, he said his focus now is on building, building, building, with several projects underway and more in the blueprint of the mind of a man who saw opportunity, seized it, became rich, and keeps applying the same formula.

“Unless there’s an adverse change in New York City, my plan is to keep expanding our real estate development business. We have about four, five, six projects ready to build,” he said, including right on the beach in Coney Island where he has three towers going up.

It’s an ambitious development of 500 units and a 22-story start. But he said he’s also ramping up the pace of developing in downtown Brooklyn, around Myrtle and Flatbush Avenue, where he bought three city blocks 30 years ago for $400,000 – and where he said the land alone now is worth $200 million.

Going up there are four residential buildings, the first already done has 110 units — studios, one-, two-, three-bedrooms — with one of his own Red Apple supermarkets and a CVS store at the bottom.

Right behind that is another building there already under construction and due to be finished in November, offering 220-230 units in a borough that has become an attractive place to live and luring people from around the country. Brooklyn is hot, and so is Catsimatidis, who said he’ll lay the foundation this spring for another building on the site and then a fourth one, a 40-story tower.

He has more plans for Manhattan as well, including tearing down a building he bought at 56^th Street and 11^th Avenue to erect a 22-story structure that is likely to be part hotel, residential or office.

He’s optimistic about the city’s business prospects, with the caveat that it could be undone politically. “New York is going to hit new highs — unless there’s something that the new mayor does that hurts the city. What could hurt it? Street crime could hurt it; adverse increase in taxes could hurt it; adverse demands for housing with an increase of 80/20 may hurt it. I could spend the next couple million dollars building in New York City, or I could spend the next couple million dollars building in Florida.”

But for now, he’s in a New York state of mind and still working hard. “To me, the definition of retirement is working four days a week,” he said.