NEW YORK, Nov 17 (Reuters) - William Pollak, the longtime president and chief executive officer of American Lawyer Media, said he is leaving the company early next year.

ALM owns some of the legal industry's best-known publications, including The American Lawyer, The National Law Journal and The New York Law Journal. ALM is a competitor of Thomson Reuters.

ALM made the announcement today. In an internal email to ALM employees which was obtained by Reuters, Pollak said he would "assist with the transition of the company to new leadership" and was "evaluating opportunities" for his next step. "As the company prepares to define the next phase of its development, this seemed to be an appropriate time to transition ALM's leadership to its next chief executive," he wrote.

Neither the email nor the company's press release named a successor to Pollak, who said in the email that his departure was his decision.

The move follows a recent executive shake-up at the company and a period of turmoil and transition in the ownership of ALM. Senior vice presidents George Dillehay and Jack Berkowitz unexpectedly left the company earlier this year.

Business-information provider Incisive Media bought American Lawyer Media in 2007 for $630 million dollars, which doubled Incisive Media's size, Reuters reported. The move was intended to provide a more balanced division between the company's United States and European businesses, Incisive said at the time. Two years later, Incisive split into two companies and its private equity owners, Apax Partners, kept control of ALM.

The search for a new CEO at ALM comes at a time when publishers of legal news are jostling to dominate the business. In April, ALM announced that it would enter into a multi-year agreement with LexisNexis, a provider of legal, corporate and academic content. The deal made Lexis the exclusive third-party online distributor of ALM content. In August, Bloomberg LP, in a move to shore up its legal business, said it would buy legal tax and regulatory research company BNA for about $990 million.

Bloomberg Law competes with Thomson Reuters' Westlaw legal database and with LexisNexis.

Pollak has served as ALM's president, CEO and a member of its board since the company's formation in 1998. Prior to that, he held a variety of positions at The New York Times.

A call to Pollak was referred to an ALM spokesperson. He declined to comment beyond the press release. A call to Apax Partners was not immediately returned.

(Reporting by Erin Geiger Smith)

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