The arrests, which came to a head in September, were one of the biggest busts of Mexican operatives working with European counterparts. They came as Mexican cartels move in on trafficking routes traditionally dominated by Colombians, who produce most of the world’s cocaine, experts say.

Mexican President Felipe Calderon has deployed thousands of soldiers and federal police to dangerous U.S.-Mexico border towns to take on drug gangs after coming to office in 2006.

“Given the pressure from the Calderon government, we are seeing some of the Mexican groups seeking alliances with Europeans,” University of Miami drug expert Bruce Bagley said.

Cocaine can be sold for more than four times as much in Europe as in the United States and in 2005 some 80 percent of the drug not destined for the U.S. market went to Europe, according to the United Nations.

The U.S. government estimates cocaine consumption in western Europe has increased nearly 60 percent since 1998, creating huge opportunities for profit.

The shift comes as Colombian cartels are splintering from years of government pressure, opening more trans-Atlantic opportunities for Mexican gangs either collaborating with or working around the Colombians.

The capture in Spain in September of top Colombian cartel member Edgar Vallejo, who pioneered trafficking routes to Europe via Africa, has made room for Mexican operatives, a senior Drug Enforcement Administration official told Reuters.

“This key Colombian trafficker gets popped in Europe and had a fairly big fraction of the market and that arrest may contribute to the flux in of this entire global model of world wide dominance of cocaine distribution,” he said