"I'm very worried that Dow Jones' unique journalistic values will longterm strongly suffer after the proposed sale, " von Holtzbrinck said in a letter submitted to the US Securities and Exchange Commission.

Directors of Dow Jones voted on Tuesday to back the $60-a-share bid, turning the company's fate over to the Bancroft family, which controls 64% of the New York-based publisher. The Bancrofts are split over whether to sell the company they have controlled for more than 100 years to News Corp.

Holtzbrinck, supervisory board chairman of the German publisher Verlagsgruppe Georg von Holtzbrink GmbH, along with Leslie Hill, a Bancroft family member who serves on the board, abstained from voting on the proposed offer, the Journal reported.

"Dieter von Holtzbrinck has served Dow Jones with distinction as a director since 2001. The board has accepted his resignation with regret and we wish him well, " chairman M Peter McPherson said in a statement.

Dow Jones shares have lost 6.2% of their value since 6 July as some investors speculated the Bancrofts may oppose the sale.

The stock declined 25 cents to $55.40 at 4:01pm on Friday in New York Stock Exchange composite trading.