An investor proposal to give Ecolab Inc. shareholders more oversight over the company's political contributions was soundly defeated at Ecolab's annual meeting this week.

NorthStar Asset Management proposed that shareholders be allowed to vote on political contributions, a departure from the company's current practice of disclosing contributions after they are made.

But the initiative received only 4 percent of the votes cast, according to Securities and Exchange Commission filings.

A 2010 U.S. Supreme Court ruling that opened corporate coffers to political candidates prompted more shareholder advocacy groups like NorthStar to challenge companies over their political spending.

Investors seeking more disclosure filed 109 resolutions this year, compared with about 80 last year, according to the Sustainable Investments Institute, a proxy research group based in Washington, D.C. In a report released in February, it said a growing number of proposals also focus on spending after elections, through lobbying.

In January, two Boston investment firms, Trillium Asset Management and Green Century Capital Management, said they submitted shareholder resolutions seeking to block corporate political contributions by Target Corp. and 3M Co. Another Boston-based investor, Walden Asset Management, has proposed 3M give shareholders more information on lobbying.

The boards of both companies have recommended stockholders vote against the proposals. Maplewood-based 3M has its annual meeting Tuesday while Minneapolis-based Target's meeting is in June.

In documents filed with the Securities and Exchange Commission, Northstar said it believed some contributions by the St. Paul-based company conflicted with its stated values.

The filing named five politicians who received money, including Minnesota Republicans Michele Bachmann and John Kline. The documents noted that, among other things, both Bachmann and Kline opposed hate crime legislation, the repeal of Don't Ask/Don't Tell that was aimed at reducing discrimination in the military, and the American Clean Energy and Security Act of 2009. Their positions are at odds with Ecolab's nondiscrimination policies and publicly stated commitments to protect the environment, NorthStar said.

Ecolab's board had opposed the proposal, saying political donations are subjected to a "substantial review."

The proxy also said Ecolab's political action committee is funded by voluntary contributions from employees and that its contributions are determined by a board made up mostly of executives from the company's business units.

Susan Feyder • 612-673-1723