Swiss energy giant EGL is set to sign a 25-year deal in Teheran on Monday to buy 5.5 billion cubic meters of Iranian natural gas per year, starting in 2011, for a reported â‚¬18 billion. The contract will be the second largest European gas deal, although EGL spokesman Bogdan Preda told The Jerusalem Post, "We are not releasing the value of the deal." In April, the Austrian energy company OMV signed letters of intent with Iran valued at â‚¬22 billion to supply Europe with gas, but that contract has yet to be finalized. US officials are closely scrutinizing the legality of the OMV deal. Swiss journalist Alexander Hasgall told the Post that Switzerland had "neglected the political meaning of the gas contract and invoked the economic argument" to justify the transaction. Critics of the growing number of European-Iranian oil and gas deals argue that Teheran can use the profits for a nuclear weapons program. Preda, from EGL, told the Post that the EGL was aware of the criticism, but "we say that Europe needs to diversify its supplies of gas." Swiss Foreign Minister Micheline Calmy-Rey will be present at Monday's signing between EGL and the National Iranian Gas Export Company. The US Embassy in Bern could not be reached for comment on Sunday, but previously said, in response to a visit by an Iranian delegation to Switzerland in connection with the EGL gas deal, "New and large oil and gas deals with Iran send the wrong message at a time in which Iran continues to defy UN Security Council resolutions that demand a suspension of activities with respect to nuclear enrichment and processing." When asked if EGL had violated the US Iran Sanctions Act, an EGL spokesman said, "The Iran Sanctions Act applies when we are investing" in Iran, but EGL is "purchasing gas from Iran." A Foreign Ministry spokesman in Jerusalem said the ministry was looking into reports of the gas purchase and could not comment on this specific deal until the details were clarified. At the same time, the spokesman said Israel believed business deals with Teheran were "counterproductive." These types of deals, he said, were "unfortunate," with Israel's position being that curbing trade could have a "real impact on Iran's nuclear policy." The presence of Calmy-Rey at the signing ceremony in Teheran comes at a sensitive time because a number of European Union countries and the US are trying to restrict trade with Iran's energy and banking sectors. The Swiss Foreign Ministry did not announce Calmy-Rey's visit to Iran; shortly before her departure to Iran on Sunday, Calmy-Rey said the Iranian government had invited her to participate in the closing of the gas deal. Herb Keinon contributed to this report.