(Adds comment from Sturm Ruger, details)
By Ross Kerber
BOSTON, April 26 (Reuters) - Institutional Shareholder Services recommended investors withhold support from three directors at gunmaker Sturm Ruger & Co ahead of its May 8 annual meeting, the top proxy adviser said in a report seen by Reuters on Friday.
Sturm Ruger has been under pressure from gun control activists over how it might respond to a series of mass shootings across the United States, including at schools, houses of worship and workplaces.
ISS recommended investors withhold support from Sturm Ruger Chair Michael Jacobi and the heads of its governance and risk oversight committees. It did recommend investors back the company's six other board nominees including Chief Executive Christopher Killoy and Sandra Froman, who is also a director of the National Rifle Association and was its president from 2005 to 2007.
In a separate report, rival proxy adviser Glass Lewis recommended support for all nine of Sturm Ruger's director nominees.
Last year a majority of Sturm Ruger investors backed a call for a safety report, but ISS said the document the company produced "provides little new information."
ISS also wrote that contrary to the board's policy of non-engagement with investors, many U.S. companies routinely engage with their shareholders.
Sturm Ruger general counsel Kevin Reid said via e-mail, "We are disappointed with the ISS report and strongly disagree with the withhold recommendations."
He said the company is confident the 34-page report it issued Feb. 8 "was fully responsive to the shareholder proposal" passed last year and said investors should read it and judge for themselves, via the firm's website.
Reporting by Ross Kerber, Editing by Franklin Paul, Richard Chang and Cynthia Osterman