GENEVA, April 8 (Reuters) – Switzerland rejected accusations on Tuesday by the U.S.-based Anti-Defamation League (ADL) that it could be financing terrorism after a Swiss company clinched a multi-billion euro (dollar) deal to buy natural gas from Iran.

The Swiss Foreign Ministry reiterated that the purchase did not violate U.N. Security Council resolutions imposing sanctions on Iran over its nuclear programme or U.S. domestic law.

The American Jewish group’s full-page advertisement — which follows a complaint lodged by Israel with Switzerland over the deal — appeared on Tuesday in newspapers under the banner “Guess who is the world’s newest financier of terrorism? SWITZERLAND”.

“The reproaches in this advertisement do not correspond to the facts,” Swiss Foreign Ministry spokesman Lars Knuchel said.

The ad — which ran in the International Herald Tribune, the leading Swiss financial daily Neue Zuercher Zeitung and Geneva daily Le Temps — said the deal’s “likely result” was Hamas and Hezbollah “may get tens of thousands of additional missiles”.

Both Hezbollah, the Shi’ite Muslim movement in Lebanon, and the Palestinian Islamist group Hamas which seized control of the Gaza Strip last year, are pro-Iranian parties.

U.S. President George W. Bush has accused Shi’ite Muslim Iran of being “the world’s leading state sponsor of terror” and of undermining peace by supporting Hezbollah and Hamas.

The United States has led international efforts to penalise Iran for failing to allay suspicions that it is seeking nuclear weapons and has been urging other countries to cut trade ties.

The ad said that the contract, signed during a Tehran visit last month by Swiss Foreign Minister Micheline Calmy-Rey, would enable Iran to accelerate and complete its nuclear programme.

“Terrorist cells in Europe, the Middle East and around the globe will have access to new weapons and support,” it said. “When you finance a terrorist state, you finance terrorism.”

The Swiss energy group Elektrizitaetsgesellschaft Laufenburg (EGL) has said its 25-year deal with the National Iranian Gas Export Company was worth between 10 billion euros ($15.73 billion) and 22 billion euros, depending on several factors such as the price of oil.

Calmy-Rey, whose neutral country has worked in the past to find a compromise in the nuclear row, said in Tehran that the deal was important in the long term for both parties.

“This business transaction between the EGL and NIGEC is fully in line with the U.N. sanctions against Iran as well as with the U.S. Iranian Sanctions Act,” Knuchel said on Tuesday.

Asked whether the deal might jeopardise neutral Switzerland’s role in handling U.S. interests in Iran, as it has done since the 1979 revolution, he said a State Department spokesman had said last week there was no change in U.S. policy.

The Swiss foreign ministry also pointed out that other powers including the European Union (EU), China and Japan were doing business with the Islamic Republic. (Editing by Jonathan Lynn and Charles Dick)