NEW YORK — Billionaire investor Ron Burkle is working with a union representing workers at Dow Jones & Co. to explore alternatives to Rupert Murdoch's $5 billion bid for the company, which publishes The Wall Street Journal.

The Independent Association of Publishers' Employees said in a statement yesterday that it had reached out to Burkle, as well as billionaire investor Warren Buffett and others, in an attempt to find other potential buyers for Dow Jones. The union strongly opposes Murdoch's bid, saying he might slant the Journal's coverage to suit his business interests.

Burkle, who made a fortune investing in supermarket chains, recently lost out on a joint bid for Tribune Co. with fellow investor Eli Broad, and also worked with newspaper unions on failed bids for Knight Ridder Inc. and for The Philadelphia Inquirer and Philadelphia Daily News.

After initially rebuffing Murdoch's offer in early May, Dow Jones' controlling shareholders, the Bancroft family, held an initial meeting with Murdoch and several of his senior executives Monday to discuss his interest in Dow Jones. IAPE, which represents about a quarter of Dow Jones employees, said it hoped the Bancrofts would decide not to sell the company, but that if they did, that they would consider alternatives to Murdoch.

Both Murdoch and a family representative said the talks Monday were "constructive," but neither provided any further detail and it was unclear when any follow-up conversations might occur. The Bancroft family has said it is "resolute" in its commitment to protect the Journal's independence and integrity.

In addition to the union, former Dow Jones Chairman and Chief Executive Peter Kann has expressed opposition to Murdoch's bid, as has former board member Jim Ottaway Jr., who controls 5 percent of the company's shareholder vote.

The Journal ran a lengthy story on its front page yesterday saying that Murdoch's media properties have made coverage decisions that advanced the interests of his media conglomerate, News Corp., blurring the line between the business and news sides of the company.

A News Corp. spokesman declined to comment on Burkle's decision to work with the Dow Jones union. News Corp. has said any concerns about Murdoch meddling with the Journal's news coverage are unwarranted. A Dow Jones spokeswoman declined to comment.

Steve Yount, president of the IAPE union, declined to identify the other investors the union had reached out to. It has also said it is consulting with Ownership Associates of Cambridge, Mass., which specializes in employee stock ownership structures and which worked with newspaper union representatives at Knight Ridder in an effort to buy the paper.

Burkle had previously expressed an interest in buying Tribune, publisher of the Los Angeles Times, Chicago Tribune and other newspapers, together with Broad, but that company eventually agreed to be taken private in a deal sponsored by Chicago real estate mogul Sam Zell.