President George W. Bush's campaign to turn Iran into an economic pariah is being rebuffed from Spain to Malaysia as countries and companies pursue long-term agreements to tap into the world's second-largest reserves of oil and gas.

Royal Dutch Shell Plc, Europe's largest oil company, and Spain's Repsol YPF SA -- which last month signed a new agreement on a three-year-old gas production project, estimated at more than $10 billion -- are among those who can ill afford to give up oil and natural-gas projects in Iran, said James Bell, president of Gas Strategies, a London-based consulting firm.