Iran�s postponement of a key oil conference in London for the fourth time last month came after US pressures on the UK government, the British news agency Reuters says.�

Minister of Petroleum Bijan Zangeneh has said Iran will hold the conference to unveil its new oil contracts in Tehran instead of London.

Reuters, citing London-based diplomatic sources, said the decision came after US officials conveyed concerns to British diplomats that the Dec. 14 event would take place before the lifting of sanctions.

The new contacts and projects for development will be introduced to foreign investors in the Iranian month of Aban which begins on Oct. 23, Zangeneh told the Ministry of Petroleum�s Shana news agency last month.

The London conference will be held in February 2016 so that the companies which miss the event in Tehran could attend it, he said.

The National Iranian Oil Company (NIOC) plans to unveil about 50 new contracts for development of the country's energy reserves which international companies are jostling to win after the removal of sanctions.

According to Reuters, US officials have recently held round�table discussions with oil industry executives and bankers in Washington and New York to reiterate that sanctions remain in effect.

Meanwhile, the Obama administration has privately warned foreign governments and US bankers against a rush by Western companies to invest in Iran's oil industry and other businesses.

Reuters says the US State Department recently cabled a �demarche� to embassies around the world to reiterate that sanctions on Iran are still in place.

"The United States wants to tell governments not to get ahead of themselves when dealing with Iran," the news agency cited an unnamed London-based diplomatic source as saying.

A number of international energy companies, such as Royal Dutch Shell, BP, France�s Total�and Italy�s Eni have sent their top executives to Iran to discuss new opportunities for trade.

The new projects will be ceded under the Iran Petroleum Contract model for a combination of brown and green fields as well as exploration blocks up for development worth about $185 billion.

By Press TV