NEW YORK (CNN/Money) - TIAA-CREF, one of the nation's largest institutional investors, has asked 1,754 major companies to treat all employee stock options as expenses, according to a published report Wednesday.

John Biggs, chairman, chief executive and president of TIAA-CREF, sent a letter to the companies, urging their boards to consider the measure, saying expensing options "contributes to clear, straightforward and high-quality financial reporting, enhancing credibility that surely will be highly valued in the post-Enron market," the Wall Street Journal reported.

Advocates of expensing options say they are compensation and should be accounted as such, especially since large option grants may dilute the value of a company's outstanding shares when exercised.

Opponents contend it is difficult to assign values to options and that expensing them would only further confuse investors.

The proposal by TIAA-CREF, which owns about 1 percent of the share of the companies targeted and has $265 billion under management, follows moves by Coca-Cola Co (KO: Research, Estimates)., Washington Post Co (WPO: Research, Estimates)., Bank One Corp (ONE: Research, Estimates)., and AMB Property Corp (AMB: Research, Estimates). to expense options, according to the paper.

Other large shareholders may follow suit. "We would consider doing something similar," Ann Yerger, research director for the Council of Institutional Investors, told the Journal. The Washington-based group represents more than 130 pension funds with more than $2 trillion in assets.