AUGUSTA, Maine — For the fourth time in a row Maine faces a broad scramble to succeed a two-term governor. Next year’s contest may become the most wide open since 1994.

Both major party nominations could be hotly contested and a number of independent figures are under close watch as Maine’s third gubernatorial campaign under the Clean Elections system that offers a public financing option gets under way.

“I think in the end there will be some newcomers and some experienced people on the ballot,” says Maine House Speaker Hannah Pingree, who’s not running.

Democrats, Republicans and Greens hold primary elections next June.

For now, Steven Rowe of Portland, a former state attorney general and House speaker, has a leg up among Democrats. Rowe, whose intention to seek the governorship in 2010 has been clear since before term limits ended his tenure as Maine’s top law enforcement officer last winter, made it official in June.

Another declared Democratic candidate is little-known state Rep. Dawn Hill of York, a lawyer and small-business owner serving her second term in the House.

On the Republican side, early activity was stirred by untested longshots: Matthew C. Jacobson, president and chief executive of Maine & Co. from Cumberland and developer Bruce Poliquin of Georgetown.

Now one-time ski mogul Les Otten of Greenwood, who has been mentioned as a potential hopeful in the past, has announced the formation of an exploratory committee.

Blaine House openings, with incumbents preparing to move on, historically spawn crowded fields.

As Gov. John McKernan was concluding a second term almost 16 years ago, an eight-way Republican gubernatorial primary was won by Susan Collins, now a U.S. senator. Joseph Brennan, a former two-term governor, bested four opponents in the Democratic Party. Both lost to independent Angus King.

This time, others are still waiting in the wings on both sides, so the field could grow.

Democrats who have been taking soundings include two members of Gov. John Baldacci’s Cabinet, conservation chief Patrick McGowan, who has previously run unsuccessfully for Congress, and economic development head John Richardson, another former speaker of the House.

Also making the rounds has been political rookie Rosa Scarcelli, a businesswoman from Portland.

Democratic lists have to include Senate President Elizabeth Mitchell, D-Vassalboro, who has served as House speaker herself, and Democratic Sens. G. William Diamond of Windham and Dennis Damon of Trenton.

Mentioned too is Robert C.S. Monks, a Cape Elizabeth businessman.

Across the political aisle, Republican state Sen. Peter Mills of Cornville, who lost a bid for the GOP gubernatorial nomination in 2006, is weighing another try. Other frequently mentioned Republican aspirants include House Minority Leader Joshua Tardy of Newport and Senate Minority Leader Kevin Raye of Perry.

Peter Cianchette, a former GOP candidate for governor, recently returned home from a stint as U.S. ambassador to Costa Rica to rejoin Cianbro, the family construction business. Cianchette’s presence has boosted the buzz in GOP circles where Steve Abbott, a longtime top aide to Collins, also has been considered a maybe.

At least one candidate is exploring a run as an independent: Eliot Cutler, a one-time aide to Sen. Edmund S. Muskie who also worked in the Carter administration. A lawyer with experience in Washington and overseas, Cutler resides in Cape Elizabeth.

And there has been recurrent talk of Cianbro Chairman Peter Vigue.

What could minimize the eventual size of the field, numerous State House observers joke, is the bleak economic outlook and the seemingly thankless task awaiting whoever wins the November 2010 balloting.

Pingree acknowledged that times are difficult financially but adds that “in turbulent times even more, you need someone who understands the political process and how to move Maine forward.”