AUGUSTA — Independent Angus King is leading the pack in contributions for Maine’s open U.S. Senate seat, and new campaign finance reports show the Democratic incumbents in the state’s two House districts are ahead of their GOP challengers.

As of June 30, King had raised nearly $900,000 and had more the $503,000 in cash on hand. Republican candidate Charlie Summers raised $240,000 through the same period and had nearly $120,000 in cash. Democrat Cynthia Dill raised more than $91,000 and had $28,500 in cash.

The Summers campaign said that $122,000 — more than half of the money raised during the second quarter — was donated after he won the GOP primary on June 12. Summers is currently Maine’s secretary of state.

Dill’s campaign said nearly 86 percent of her funding has come from small donations within Maine. She noted that her average in-state donation was just under $135.

“So, we’re confident this campaign represents the interests of ordinary Maine people, because that’s who supports us,” Dill, who is a state senator, said in a statement.

King, a former two-term governor, has been leading in polls asking who should succeed Republican Sen. Olympia Snowe, who cited polarization and political gridlock in her announcement earlier this year that she would not seek re-election.

In the U.S. House races, 1st District Democratic Rep. Chellie Pingree reports raising more than $766,000 for her re-election campaign, leaving her with $349,450 cash on hand. Republican candidate Jon Courtney raised nearly $28,300 and had $18,200 cash on hand through June 30, according to the Federal Election Commission report.

In the 2nd District, Federal Election Commission reports show Democratic Rep. Mike Michaud raised nearly $919,000, leaving him with $635,000 in cash, while Republican Kevin Raye raised $353,000 with $242,000 in cash on hand.

Raye, who is completing a term as Maine Senate president, said the pace of contributions has picked up since late May, enabling him to double his previous cash on hand.