In a significant change, the Bill & Melinda Gates Foundation announced Wednesday that it would review its investments to determine whether its holdings were socially responsible.

In addition to what it called a continuing review of "our approach to investments," the foundation said on its website, "we will review other strategies that can fulfill a social responsibility role, both in terms of their aspirations and in understanding the impact that they may have."

The announcement came two days after the Los Angeles Times published the second article in a two-part investigation showing that the foundation reaps vast financial gains every year from investments that contravene its good works.

The Times found that the organization — led and funded by the chairman of Microsoft Corp. and his wife — invested hundreds of millions of dollars in companies that contribute to the problems of health, housing and social welfare that the foundation tries to solve.

In its website statement, the foundation said it would establish a procedure in which the founder and his wife would personally assess its holdings and matters of social responsibility. "We will … formalize the process," it said, "by which Bill and Melinda Gates analyze and review these issues."

Experts in socially conscious investing said the development would probably cause other foundations to rethink their endowment policies. The David & Lucille Packard Foundation and the William & Flora Hewlett Foundation, both among the nation's 10 largest, said Wednesday that they too were reevaluating their investments to assess social and environmental effects.

"Because people are pointing out the kinds of inconsistencies between investment behavior and mission," said Lance Lindblom, president of the Nathan Cummings Foundation, which has been a leader in considering social investment issues, "we may be reaching a tipping point."

Using the most recent data available, The Times found that hundreds of Gates Foundation investments — totaling at least $8.7 billion, or 41% of its assets, not including U.S. and foreign government securities — have been in companies that countered the foundation's charitable goals or socially concerned philosophy.

During the investigation, the foundation did not respond to questions from The Times about whether it might change its investment policies, or about its holdings in specific companies flagged by services that analyze corporate behavior for failing tests of social responsibility in areas such as environmental stewardship and human rights.

Similarly, on Wednesday, the Gates Foundation would not respond to inquiries from The Times. But in an interview Tuesday with the Seattle Times, Cheryl Scott, chief operating officer of the foundation, said it would determine whether it should pull its money out of companies that harm society.

Scott told the Seattle newspaper, which published the Los Angeles Times investigation, that the foundation's method of investing its assets was "not 100% effective."

This year, for the first time, Scott said, the foundation would conduct a methodical review to find out whether "there are cases simply where the situation is so egregious it will cause us not to invest."

Scott denied to the Seattle Times that the changes in how the foundation's investments would be handled were in response to adverse publicity.

"This has been an issue that has been top of line for a long time and will continue to be."

In the foundation's statement on its website, Scott said:

"These are complicated questions, and we welcome an open discussion about them…. Of course, there will be cases where the harm caused by a particular company or industry is so evident that we will decide not to invest in it."

Scott's Web statement said the Gates Foundation pursued "program-related investments" for financial services to the poor, but it did not provide details of the investments. Unlike standard investments, program-related investments specifically support the organization's charitable goals.

Before Wednesday's announcement, Gates Foundation records showed, it had made only one program-related investment: a $1.4-million interest-free loan to a Seattle school.

On Wednesday afternoon the foundation removed the new investment policy statement from its website. A spokesperson said the statement would be reposted with additional information.