By Martha Graybow

NEW YORK, April 16 (Reuters) - A proposal to give shareholders at Eli Lilly and Co (LLY.N: Quote, Profile, Research) the power to amend the drugmaker's bylaws has won the support of four proxy advisory services, the California Public Employees' Retirement System said on Wednesday.

Calpers, the biggest U.S. pension fund with assets of about $235 billion, has submitted the proposal for consideration at the company's April 21 annual meeting. It also plans to withhold votes for three company directors up for re-election, including the new chief executive, John Lechleiter.

The bylaws proposal is supported by U.S. proxy advisory firms RiskMetrics Group Inc (RMG.N: Quote, Profile, Research), Glass Lewis, Egan-Jones and Proxy Governance, Calpers said in a statement. The pension fund's nonbinding resolution asks that shareowners be allowed to amend company bylaws by a majority vote.

Giving shareholders the ability to amend the bylaws is a key tool for influencing a company's governance practices and ensuring boards are accountable, Calpers contends.

Shareowners can amend bylaws at about 95 percent of companies in the Standard & Poor's 500 and Russell 1000 indexes, according to Calpers. It said it named Lilly to its Focus List of underperforming companies in 2007, partly because the company doesn't allow shareowners to amend bylaws.

Calpers said that as of the end of March, the Indianapolis-based company's stock had significantly underperformed both the S&P 500 and the S&P 500 Health Care indexes. Lilly trailed index peers by 22.41 percent and the S&P 500 by 67.65 percent over five years, the pension fund said.

Calpers owns about 4.8 million Lilly shares worth an estimated $265 million in its portfolio.

A Lilly representative was not immediately available for comment.