Latham & Watkins is finally winding down its Newark office, which suffered a mass exodus of attorneys six years ago and never fully recovered.

The Newark branch, which peaked at more than 40 lawyers in the mid-2000s, as of Thursday was down to four partners and four associates. Most will be relocated to New York, along with the remaining support staff.

A spokesman, Geoff Burt, says the firm will keep a small office in Newark for the convenience of clients and two partners will split their time between here and New York.

Alan Kraus and Keena Hausmann, the two partners who will cover the Newark office parttime, did not return calls on Thursday.

Latham & Watkins ranked fourth this year in the Am Law 100, The American Lawyer‘s survey of the nation’s highest-grossing firms, with 2011 revenues of $2.15 billion. It has roughly 2,000 lawyers in about 30 branch offices.

The firm’s managing partner, Robert Dell, who is resident in the San Francisco office, did not return a reporter’s call.

The Newark office opened with a fanfare in 1994 when outgoing U.S. Attorney Michael Chertoff became its partner in charge. By the time Chertoff left in 2001 to return to the U.S. Department of Justice, the firm had grown to 25 lawyers.

It had reached its apex of 41 lawyers in 2006 when a 30-lawyer group, led by mass-tort and product-liability litigator James Tyrrell Jr., decamped to Patton Boggs of Washington, D.C., which was establishing beachheads in Newark and New York.

The defection deflated Latham’s Newark presence. Tyrrell had headed the office from 2000 to 2004 and was one of its biggest rainmakers, bringing in work from Monsanto Co. and Lucent Technologies Inc. He told The American Lawyer in 2006 that his book of business exceeded $20 million in some years.

“Since then, they really had a fragile office,” says Stewart Cohen, of Topaz Attorney Search in Livingston. “They never really could rebuild it.”

Economic justification for the Newark office weakened as the lawyer count declined, according to two sources familiar with its operations.

The office was also hampered by Latham’s policy of keeping its hourly rates at the same level for all of its offices. They tended to be higher than those of leading New Jersey firms, putting off some local clients, Cohen says.

Costlier New York-level hourly rates similarly spelled the end of Skadden, Arps, Slate, Meagher & Flom’s Newark office, which closed in 2004 after 10 years.

Ultimately, Latham found it didn’t need a full-scale New Jersey office to serve its New Jersey clients, says one person familiar with the firm. “For whatever reason, they didn’t make that decision quickly or lightly,” a source says.