PORTLAND, Maine (AP) -- Calling it a first in the state's political history, independent U.S. Senate candidate Angus King on Monday released seven years' worth of federal tax returns showing that he and his wife earned on average nearly $570,000 a year and paid an average federal income taxes of 22.2 percent during the period.
King's tax returns also showed that he and his wife, Mary Herman, made average charitable contributions of 13.4 percent, or about $76,000 per year, with most going to Maine charities.
"It's all there. We're being fully transparent," King campaign spokeswoman Crystal Canney said.
King's campaign, which believes it's the widest release of personal financial records produced in the history of Maine politics, responded to a challenge by Democrat Cynthia Dill. She had urged the three major candidates to release 10 years' worth of tax returns through a trusted third party.
Dill said Monday that she was prepared to release tax returns, but gave no timetable for doing so. Republican Charlie Summers planned to release his Monday night.
King released his documents -- hundreds of pages -- through his campaign instead of through a third party. Seven years' worth of tax returns is all that his accountant kept and all that's required by the Internal Revenue Service, Canney said. King didn't keep the older returns, she said.
The majority of King's wealth comes from the sale of his energy conservation company, Northeast Energy Management, before running for governor.
Over the seven-year period, the family's gross income ranged from $490,486 to $665,485, according to his accountant. The tax rate on his earnings fluctuated between 20 percent and 26.4 percent, which reflected the fact that much of his income came from capital gains on the stock sales, which are taxed at 15 percent. King's capital gains averaged $231,206 during the period.
At a recent debate in Lewiston, King advocated for raising the capital gains tax rate to make it the same as taxes for other income, a position on which Dill agrees with him. Summers, in contrast, proposed eliminating the capital gains tax altogether to encourage people to reinvest the earnings in the economy.
The documents show King and Herman contributed thousands of dollars to charities, often in the form of stock transfers.
Beneficiaries included Guatemalan charity Safe Passage, the Maine Community Foundation, the University of New England, and a school building fund on North Haven Island, where Rep. Chellie Pingree has a home. Other donations included Family Crisis Services Endowment and Family Planning Association of Maine.
Dill's proposal came against a backdrop of a similar debate in the presidential race in which Republican Mitt Romney refused to release returns before 2010.
"Releasing our federal tax returns would provide that antidote of sunshine, which is so crucial to the functioning of a healthy, robust democracy," she wrote.
Three other independents in the race -- Steve Woods of Yarmouth, Danny Dalton of Brunswick and Andrew Ian Dodge of Harpswell -- were not included in Dill's proposal.