Montgomery County Council member and county executive candidate Nancy Floreen (I) early this month in Gaithersburg. (Sarah L. Voisin/The Washington Post)

Nancy Floreen, the Democrat turned independent making a bid for Montgomery County executive, has raised more than $340,000 for the effort — much of it from real estate developers and business leaders.

Floreen, a 16-year at-large County Council member, shed her longtime party affiliation to run for Montgomery’s top elected position after Marc Elrich was declared the winner of the June 26 Democratic primary.

She has raised $342,015 and spent $206,207.25, according to a campaign finance report filed Tuesday. The report covered the period between July 2 and Aug. 21, although Floreen said she held off soliciting money until she changed her voter registration July 9.

Elrich won the Democratic nomination by 77 votes over Potomac businessman David Blair in the six-person race. Their tight battle for the nomination came down to absentee and provisional ballots, as well as a partial recount of the results that Blair requested. Blair has since thrown his support behind Elrich.

Floreen, a moderate who is favored by business leaders, and Elrich, championed by unions and progressive groups, are at odds on several issues, with the starkest differences being their stances on development in the county.

They are competing with Republican Robin Ficker to succeed longtime county executive Isiah Leggett (D), who has expressed admiration for Floreen but says he will support Elrich as the Democratic nominee.

Marc Elrich, an at-large County Council member and now the Democratic nominee for Montgomery County executive, at a November debate in Chevy Chase. (Katherine Frey/The Washington Post)

Elrich has maintained that he wants developers to bear more of the costs of alleviating traffic congestion and school crowding in Maryland’s most populous jurisdiction. Floreen, who previously served on the county’s Planning Board, says Montgomery already has demanding rules in place that developers must follow to build.

Of the 129 donations Floreen reported, 35 were at the $6,000 limit for candidates who are not participating in the county’s public financing system.

The donors include a who’s who of prominent real estate developers and business leaders in the county, such as Charles K. Nulsen, president of Washington Property Co. in Bethesda, and Christopher Bruch, president and chief executive of the Donohoe Cos., a real estate and development firm also in Bethesda.

Floreen reported spending $180,855.11 on two firms she retained to gather petition signatures to allow her to appear on the November ballot — District-based FieldWorks and the North, a consulting group based in Minneapolis.

Elrich, who is using the public financing system, has received more than $787,000 in public matching funds. Late Tuesday, he reported receiving campaign contributions of $14,604 between July 17 and Aug. 21. He has requested another $56,864 in public funds, according to his filings.

Republican county executive nominee Robin Ficker delivers petition signatures to the executive’s office in Rockville early this month. (Bill Turque/The Washington Post)

Ficker, who also has qualified for public financing, has received $231,185 in public funds. He reported receiving $2,230 in donations between June 11 and Aug. 21, and asked for another $12,330 in public funds.

This story was updated Wednesday morning to include the latest filings from Elrich and Ficker.