Several shipping companies have launched a legal challenge against the European Union after the bloc imposed sanctions on them over their suspected involvement in Iran's nuclear programme and arms trafficking, a court application showed.

In May the EU extended its sanctions adding more than 100 new entities to a list of companies and people affected, including those it said were owned or controlled by the Islamic Republic of Iran Shipping Lines (IRISL), already targeted under previous measures.

In a summary application filed last week with the General Court of the European Union in Luxembourg, 36 entities led by Hamburg based shipping firm Ocean Capital Administration sought an annulment of financial sanctions which, they said had led to an EU-wide freeze of their assets.

"The result is that they are unable to trade or carry out business at all within the EU, and are not able to obtain insurance or reinsurance for hull or machinery from any European company, and it is prohibited to load or unload their cargoes in EU ports," the application said.

The companies, based in Germany, Malta and Cyprus, said the financial effects and damage to their reputation from the "serious allegations" was enormous.

"This is incorrect, unsubstantiated and unjustified. None of the applicants is engaged in, directly associated with, or provides support for, Iran's proliferation-sensitive activities, or the development of Iran's nuclear weapon delivery systems," they said.

"None of the applicants is owned or controlled by an entity that is engaged in or supports such activities."

The EU move was part of a wider sanctions campaign led by Western states aimed mostly at forcing Tehran to curb its nuclear energy drive, which they suspect is meant to develop atomic bombs. Iran denies this, saying it wants nuclear energy only for electricity or medical treatments.

"The European Commission is fully aware of legal proceedings initiated by IRISL at the EU's General Court and is intervening in these cases in order to defend the legality of EU sanctions," a Commission spokesman said.

Maryam Taher, with M Taher & Co Solicitors representing the 36 entities, said this was the second annulment application made. The first was filed by the law firm in October 2010 on behalf of IRISL directly and 19 other companies against the Council of the European Union.

"According to our instructions IRISL have always maintained that it is not state owned or state sponsored company," she told Reuters.

In recent months IRISL has faced sanctions-related pressure from both the EU and the United States, which have said the shipping line has engaged in illegal activity, which the company has denied.

"The Council of the European Union have not submitted any evidence linking IRISL to the nuclear proliferation activities of Iran which is the only basis for imposing asset freezing measures against an entity under the EU," the shipping line said in its October application.

Sanctions have caused several IRISL vessels to have been temporarily seized in foreign ports in recent months. Earlier this year, loss of business due to sanctions pushed Johnson Stevens Agencies Ltd, the UK's leading British ship line agent that used to represent IRISL, into administration.

IRISL was at the centre of a trade scandal in Israel this year. It has denied any involvement. (Reuters)