Sen. Chuck Fuschillo, one of the so-called “Long Island nine” members of the GOP conference, is resigning, effective at 11:59 p.m. tonight, to take a job in the private sector.

This opens up a key seat at a time when the Republicans can ill afford to lose one, and no doubt will spark a fierce battle in 2014.

In a statement released this afternoon, Fuschillo called his departure a “hard and bittersweet decision to reach,” but also said he’s at a point in his life at which he’s ready for a “new challenge.”

Fuschillo, who is currently in his eighth term representing his Suffolk County district, will become CEO of the Alzheimer’s Foundation of America

“This is a new and exciting opportunity which will allow me to continue to help improve the lives of others while at the same time enabling me to spend more time with my family,” Fuschillo said.

“Though I will be leaving office, I will continue to be active in serving the community and remain engaged in the issues that are important to all of us.”

“Serving in the Senate is both an honor and privilege which I will always cherish and be forever grateful. I thank everyone in the community for giving me that privilege and wish each of you the very best in the future.”

It had been speculated for some time that Fuschillo’s days in the Senate were numbered. He had lost at least one lucrative private sector offer in the past at the request of the GOP leadership as the conference struggled to maintain its slim hold on the majority.

In 2012, the Republicans lost the majority, but managed to maintain a semblance of control over the chamber by entering into a power-sharing agreement with four renegade Democratic senators known as the IDC.

Fuschillo’s district – the 8th – has been Democrat dominated for some time (84,158 enrolled Democrats to 77,444 Republicans with 49,552 blanks as of November). The senator, like many of his GOP colleagues in similarly split districts, had been holding onto his seat thanks to the power of both personality and incumbency.

The most likely candidate on the Democrats’ side, according to one Capitol source, is County Legislator Dave Denenberg (although he had a little voter fraud problem back in 2005).

On the GOP side, the first name that popped up was Assemblyman Joseph Saladino, but I’m sure there will be more local contenders scrambling for the rare opportunity of running for an open Senate seat.

Fuschillo’s departure means there will be at least two empty Senate seats come Jan. 1. The other belonged to Eric Adams, who was elected to the post of Brooklyn borough president this past fall.

So far, Gov. Andrew Cuomo has shown no interest in calling special elections to fill empty legislative seats, since the candidate selection is inherently political and falls to the county chairs. Also, turnout in these contests tends to be very low.

If Cuomo lets this seat sit empty until the 2014 elections it could help his fellow Democrats, giving them more time to marshal their resources, and find a strong candidate to run.

Also, Cuomo’s own name on the ticket in the fall (he’ll be seeking his second four-year term) might draw Democrats out to vote in larger numbers – assuming, that is, there’s anything resembling a real challenger.

One thing is for sure: This move by Fuschillo, which seems to come with very little warning, creates an extra headache heading into 2014 for Senate GOP Leader Dean Skelos.

Skelos released the following statement in response to Fuschillo’s announcement:

It has been a great honor and pleasure to serve with Senator Chuck Fuschillo.”

“During his 15 years in the Senate, he has established an impressive legislative record that includes toughening the state’s DWI laws, protecting consumers from identity theft, creating the state’s ‘Do Not Call’ list, ensuring insurance coverage for people with autism, and encouraging the growth of Long Island’s biotechnology industry.”

“As chairman of the Senate Transportation Committee, he fought to ensure New York’s roads, bridges and mass transit systems are safe and reliable.”

“In addition to his legislative record, Chuck Fuschillo established a very close relationship with his constituents by providing them with outstanding services and community programs.”

“I know he will continue to be supportive of the efforts of the Senate Republican Conference as we continue our fight to reduce taxes, create jobs and provide greater opportunities for all New Yorkers.”

“Chuck is a good friend and colleague and he will be missed. Sometimes in life, we are presented with opportunities that are simply too good to pass up. This was one of those moments. I wish Chuck and his family the very best as he begins a new chapter of his life.”