July 30 (Bloomberg) -- Merck & Co. will have to defend itself in a class-action lawsuit over its Vioxx painkiller in New Jersey, a state judge has ruled.

Superior Court Judge Carol E. Higbee, in Atlantic County, New Jersey, agreed yesterday to certify as a class action a suit brought by the International Union of Operating Engineers Local 68 on behalf of all third-party payors, such as health- maintenance organizations, managed-care organizations, employers and unions. The ruling creates the largest single claim to date against Merck.

``Under the facts of this case with the Merck Corporation being located in New Jersey and New Jersey being applicable, the location of the third party payors class action belongs in the jurisdiction of the New Jersey state court system,'' Higbee said in a 70-page ruling.

Merck, the U.S.'s third-largest drugmaker, withdrew Vioxx in September 2004 after research showed users had a greater risk of heart attacks and strokes. It was the world's biggest drug recall.

A Merck spokesman, Christopher Loder, couldn't immediately be reached for comment on the ruling today. Merck, which has said it will fight every lawsuit, opposed the request for class certification.

No Desire to Interfere

In her ruling, Higbee said about 2,200 Vioxx lawsuits have been filed in New Jersey, the largest number of personal injury suits to be filed in any state.

The federal judge in New Orleans who is overseeing the consolidated Vioxx cases in the federal court system has met with state judges and ``assured the state court judges that the federal court has no desire to interfere in the proceedings that were already much more advanced in the state courts,'' Higbee said in her ruling.

``This is probably a unique case where the class action attorneys here have already participated in over 50 depositions of Merck corporate employees, reviewed over 7 million documents and prepared several personal injury cases for trial and moved for class certification before discovery on the class certification process has even taken place in federal court,'' Higbee said in her ruling.

Billions in Sales

Whitehouse Station, New Jersey-based Merck has set aside $675 million to fight Vioxx suits, which are expected to number in the thousands. The company's shares have fallen about 31 percent since the drug was withdrawn, cutting its value by about $30 billion.

Vioxx generated $2.5 billion in sales last year, about 11 percent of Merck's total. Merrill Lynch & Co. has estimated that Merck's liabilities for Vioxx suits could reach $18 billion.

The first Vioxx personal injury lawsuit, in Texas, began July 14.

Shares of Merck fell 23 cents to $31.06 yesterday in New York Stock Exchange composite trading. The stock is down 3.7 percent year to date.

News of the class action was reported earlier by The Wall Street Journal.

To contact the reporter on this story: Christopher Mumma in New York at at cmumma@bloomberg.net.

Last Updated: July 30, 2005 12:11 EDT