The lineup has shifted at America Online, but the game plan remains the same.

Jimmy de Castro, the former radio executive who joined

AOL Time Warner

(AOL)

seven months ago to run the AOL flagship online service, announced Tuesday he was leaving to "seek new opportunities."

While de Castro's departure underscores the ascendance of Jon Miller, who was named chairman and CEO of the America Online division in August, it doesn't appear to signal any change in AOL's newly rediscovered strategy of perfecting the user experience through promotion of exclusive content.

De Castro "deserves a huge amount of credit ... for putting the company's focus back where it belongs -- on the member," said Miller in a statement. "Jimmy infused the whole place with new energy, and assembled a world-class team that has restored the sizzle to our brand by creating innovative, must-have new programming."

In a press release, de Castro and AOL make reference to his desire to run his own organization -- a situation that presumably eluded him at AOL after Miller arrived. AOL said in September, for example, that Miller was taking a "more direct role overseeing key units" such as the AOL flagship operation. In the accompanying reorganization, AOL said that the interactive marketing chief at AOL would report directly to Miller instead of to de Castro.

AOL Time Warner's shares were recently rising 20 cents Tuesday afternoon to trade at $15.15.

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