Philadelphia Media Holdings, the company that owns the third oldest surviving newspaper in the US, The Philadelphia Inquirer, has expressed its interested in mounting a rival bid for the Dow Jones media group, which owns the prestigious The Wall Street Journal.

Brian Tierney, chief executive, Philadelphia Media Holdings, has indicated that his firm would be willing to match Rupert Murdoch''s current bid. Murdoch''s News Corporation has made a $50-billion offer for Doe Jones in early May.

Tierney said, "We don''t believe News Corporation is overpaying. This is one of the greatest journalistic enterprises ever created." Dow Jones has yet to decide on the News Corp offer.

The unions, however, opposed to the News Corp offer. The main union at Dow Jones, the Independent Association of Publishers'' Employees (IAPE), has said an unnamed internet entrepreneur and a Wall Street group were also considering putting up a rival bid.

Earlier on Tuesday, the union had said billionaire investors Ron Burkle was working with them to mount a rival bid for Dow Jones. Last year Burkle had made an unsuccessful attempt to buy the Tribune.

The IAPE has also been talks with legendary investor Warren Buffett for a possible take over offer. Buffett, however, had said last month that it was "very, very unlikely" that he would bid for Dow Jones, either as a personal investment or through his company Berkshire Hathaway, due to Murdoch''s high bid.

The IAPE has also said that it would talk to any other parties interested in making an offer for the group.

However, for any of the contenders to succeed, they must first get approval from the majority shareholder, the Bancroft family, which controls 64 per cent of the voting rights.

Murdoch has already held his first meeting with members of Bancroft family earlier this week, and while both sides said the talks were "constructive", the two could not agree on the editorial independence of the newspaper assets of The wall Street Journal, though Murdoch has promised to establish "an independent, autonomous editorial board" for the newspaper if his bid for Dow Jones is accepted.

The main US share index is named after the Dow Jones company.