The Independent Democratic Conference has formally registered a political action committee with the state Board of Elections, a sign the experiment is maturing beyond a legislative voting bloc.

Though the PAC, dubbed the IDC Initiative, shows no donations yet, the formation of the committee shows how the eight-month-old conference is trying to expand its power and influence beyond four members.

The committee was formed in August.

The IDC is composed of Sens. Jeff Klein of the Bronx, Diane Savino of Staten Island, David Carlucci of Rockland County and David Valesky of Oneida. The lawmakers defected from the larger Democratic conference after the party lost its majority last year.

Political action committees allow for more flexible fund raising and spending practices compared to candidate committees, and are often used to form legislative alliances down the road.

Klein, in particular, is a prodigious fundraiser. In the last reporting period, he raised $422,000 and is sitting on $655,000 over the last six months. The four IDC members have a combined $1 million in the bank.

Klein led the Senate Democratic Campaign Committee for two terms, and has had the luxury of never facing a stiff opponent since he was first elected.

The Independent Democrats’ PAC comes as Sen. Liz Krueger, D-Manhattan, forms her own political action committee, No Bad Apples. The PAC’s mission is to recruit reform-minded candidates, but will also serve the purpose of further consolidating Krueger’s power over the factious conference.

For the four-member IDC, helping (and possibly recruiting) candidates down the road could give them even more leverage in the closely divided Senate. Republicans hold a 32-30 majority.

And seen another way, the IDC may be gearing up its fundraising prowess in an effort to protect itself from challenges in either a general or primary election. Both Valesky and Carlucci live in moderate, Republican-heavy districts.

“Stayed tuned,” IDC spokesman Rich Azzopardi said.

The remaining Senate Democrats grumbled last year that Klein, the conference’s defacto leader, took his proverbial ball and went home after he failed to take out John Sampson.

The IDC has formed a noticeably tight alliance with Senate Republicans on several key votes, including a measure that would prevent independent redistricting for another decade, further frustrating Democratic lawmakers.

But IDC points to not wanting to have anything to do with the conference’s perceived incompetence and ineffectiveness, along with its whiffs of scandal and corruption.