SOUTH PORTLAND — Five Republican candidates for Maine’s open U.S. Senate seat blasted the record of former Gov. Angus King and touted their own business credentials during a forum Wednesday morning sponsored by the Portland Regional Chamber.

Former Maine Senate President Rick Bennett, Maine Assistant Senate Majority Leader Debra Plowman, state Treasurer Bruce Poliquin, Attorney General William Schneider and Secretary of State Charlie Summers appealed for support from nearly 100 small-business owners and others at the Sable Oaks Marriott.

Scott D’Amboise was the only candidate who missed the event. He was out of town attending to a family matter, said Chris Hall, the chamber’s executive vice president and the moderator of the forum.

The six Republicans are running in the June 12 primary election for a chance to campaign this fall to succeed Sen. Olympia Snowe, R-Maine. The four Democrats seeking their party’s nomination gathered for a similar small-business forum last week.

Each Republican candidate said they would fight in Washington to reduce federal spending and regulation that threatens the economy and strains small businesses.

Each also emphasized personal experience as a small business owner, such as Schneider’s alpaca farm and Plowman’s garage door company. Bennett also is the CEO of an investment-research company, Poliquin had a long career in corporate finance, and Summers was regional administrator for the U.S. Small Business Administration.

Less than three weeks before the primary, the candidates remained friendly — even complimentary — toward each other. They weren’t so charitable about King, who is running for Snowe’s seat as an independent and has been deemed the likely winner by the national press.

“He has never had to run on his record. He has only had to run on his personality. Personality doesn’t get you anywhere in the U.S. Senate, except in the corner hoping to cut a deal,” Plowman said.

“He served during eight of the best economic years of our recent history and he left with a billion-dollar deficit,” Schneider said.

“He is a big-government, big-spending liberal. … There will be so much money coming into this election (from national groups) that Mr. King’s record will be exposed,” Poliquin said.

“I think Angus King will beat himself. His record speaks for itself,” Summers said.

Bennett said King tied himself to the record of the Obama administration when he endorsed the president. “We can take on Angus King on his private record, his public record and his endorsement of Barack Obama.”

King, who as an independent won’t appear on any ballot in June, has yet to file nomination papers to run in November. Polls and national pundits have said his statewide popularity makes him the clear front-runner.