(Reuters) -The White House is exploring new measures to curb the influence of proxy advisers and index-fund managers, the Wall Street Journal reported on Wednesday citing people familiar with the matter.

Trump administration officials are discussing at least one executive order that would restrict proxy-advisory firms such as Institutional Shareholder Services and Glass Lewis, the Journal's report added.

Officials are also exploring limits on how index-fund managers are allowed to vote, the report said.

"As a registered investment advisor that has been subject to oversight by the SEC for a quarter of a century, ISS is committed to fulfilling its fiduciary duties to clients and operating in a transparent and ethical manner," an ISS spokesperson said in an emailed statement to Reuters.

Representatives for the White House and Glass Lewis did not immediately respond to Reuters' requests for comment. Reuters could not independently verify the report.

Glass Lewis and ISS, the two largest U.S. proxy advisory firms, analyze shareholder proposals and corporate governance issues and provide voting recommendations to institutional investors ahead of annual meetings.

Both firms have long drawn criticism for their influential voting recommendations, traditionally from corporate executives, but their guidance remains widely used by institutional investors.

Meanwhile, index-fund managers such as Vanguard, BlackRock and State Street also manage and own the stock of some of the biggest U.S. publicly traded companies.