Although the board voted the company be sold to Rupert Murdoch's News Corp. in a $5 billion takeover bid, Von Holtzbrinck wrote he could not agree with the board, and he did not vote on the proposal.

“Although I'm convinced that News Corp.'s offer is very generous in financial terms, I'm very worried that Dow Jones unique journalistic values will long-term strongly suffer after the proposed sale,” he wrote from Stuttgart.

Von Holtzbrinck wrote that board members are charged with voting for the deal that is in the best financial interest to shareholders, unless it can be proved the deal is risky.

“I cannot prove that my worries are right. I can only refer to News Corp. business practices in the past, can only refer to Jim Ottaway's article in the Journal, etc. I do not believe that the "Special Committee" can finally prevent Murdoch from doing what he wants to do, from acting his way,” he wrote.

A director on the Dow Jones board since 2001, Von Holtzbrinck is also an heir to the von Holtzbrinck publishing empire, The Wall Street Journal has reported.