The US authorities are concerned that a licence to use BP's leading synthetic fibre know-how would allow the Iranians to produce hydrogen cyanide, a gas used unsuccessfully as a weapon in the First World War.
A spokesman for BP said the company had assured the State Department that any plant it designed in Iran would not be able to produce chemical weapons as a by-product. He added that hydrogen cyanide had no military use as it was lighter than air and disappeared into the atmosphere before it could cause any damage.
BP said the gas could be produced relatively cheaply and was widely available on the open market. A decision on whether to approve the licence sale was expected within the next few weeks.
Tehran approached BP about 18 months ago to try to secure its acrylonitrile technology, since when the company has received approval from the Defence, Energy and Commerce departments in Washington. Although the State Department could not block the deal, BP admitted that it would not go ahead with the sale of the licence without the department's approval.
Acrylonitrile is a raw material used to make synthetic fibres and plastics. About 95 per cent of the world's production uses BP's technology. A plant costs dollars 250m- dollars 300m ( pounds 170m- pounds 200m) to build but analysts think the sale of the licence would be worth only a few million pounds to BP.
BP plans to sell assets worth dollars 600m from its worldwide chemicals operations over the next three years, in addition to routine licence sales. The disposals are part of a dollars 5bn programme to cut borrowings of almost dollars 16bn.Reuse content