May 29 (Reuters) - Top mutual fund manager Vanguard

Group on Thursday said it would roughly triple to 10 million the

number of investors eligible to direct proxy votes in their

funds, continuing an effort that would reduce the firm's direct

impact on shareholder elections.

Closely-held Vanguard said it added four equity index funds

to its "Investor Choice" program, bringing it to nearly $1

trillion in eligible assets from around $250 million previously.

Vanguard has $10.1 trillion in total assets.

Participating investors do not specify votes at specific

companies, but rather choose among several policy options

including one that backs company recommendations and options

that tend to support, or oppose, environmental and social

matters in corporate elections.

Other fund firms including BlackRock ( BLK ) and Charles

Schwab's asset management arm have developed similar programs.

At a time when the industry faces growing scrutiny of its

influential votes, the programs could diminish the criticism

facing the managers themselves.

Last year Vanguard's stewardship chief said only 2% of

eligible investors opted in to a previous version of its

voting-choice program, but vowed to keep building it.