Heyday Films and 1492 Pictures
So Warner Brothers is the big name studio company that distributed Chamber of Secrets (and all the other Harry Potter films). That's why you'll see their logo on the big screen when the movie starts.
But the day-to-day production grind was actually handled by two other smaller studios—Heyday Films and 1492 Pictures.
Heyday Films is named after British producer David Heyman. This guy worked in Hollywood for United Artists before coming home to the U.K. to set up his own studio. He'd only produced one other movie when he bought the rights to the Harry Potter novels back in 1999. (Source) That was way early in the magical timeline and Heyman's smart thinking meant he had struck serious gold (or serious galleons, as the goblins at Gringotts might say).
1492 Pictures came on board when director, Chris Columbus, was hired. 1492 is the film company that Columbus set up in 1995 to handle all his film projects. (Get it? Chris Columbus? 1492? You get it.)
Chamber of Secrets would go on to be a huge hit for both studios grossing over $261 million. Bank like that would mean both producers could go on making films into infinity if they wanted to. Heyman would put out critical hits like I Am Legend and Gravity. 1492 Pictures would go onto to produce more fun family fare like Night at the Museum and Percy Jackson & the Olympians.
Sure, it was all good. But nothing was gonna top the magic of Harry Potter. Sorry, Percy Jackson.