Outside groups have spent $3.47 million on state races, shattering the $1.5 million record set in 2010, according to updated campaign finance records at the Maine Ethics Commission.

For the first time, outside groups have spent over $100,000 on eight state Senate races, including three races over $200,000.

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In addition, outside groups have spent nearly a half-million dollars on a single state Senate race – District 32 in Bangor – where Republican incumbent Nichi Farnham faces Democratic challenger Geoffrey Gratwick.

A large portion of the campaign spending has been directed by Democratic and Republican Party committees, which currently lead the list of group spending. While the parties have Maine-based donors, large outside interests are also bankrolling the party spending, ethics commission records show.

For Republicans and their political action committee surrogates, the largest donations have come from the Republican State Leadership Committee, a national group funded by insurance, pharmaceutical and tobacco companies, and other industries. The RSLC has now given $795,000 to Maine PACs this election cycle, nearly double the $400,000 it spent in 2010.

For Democrats and their PAC allies, the biggest donors and spenders have been organized labor. The Washington, D.C.-based Democratic Legislative Campaign Committee has been one of the largest contributors, giving $405,000 to Democratic PACs. The group, bankrolled largely by national labor groups, gave just $81,000 to impact Maine races in 2010.

This story will be updated.