By Jonathan Saul
LONDON (Reuters) - Mohammad Souri, chairman and chief executive of NITC, has stepped down after 26 years at the helm just as Iran's biggest tanker group faces the threat of sanctions in the United States.
Shipping and oil industry sources said there was speculation Souri's departure could be linked to moves by Iranian President Mahmoud Ahmadinejad to entrench his authority in key strategic sectors, notably transportation and energy.
The National Iranian Tanker Company was privatized in 2000 and is owned by three Iranian pension funds. It is in the sanctions firing line with the U.S. senate discussing provisions that could blacklist the group.
A senior NITC official told Reuters last week that it denied any link with Iran's Revolutionary Guards, a connection alleged by supporters of the proposed new U.S. sanctions.
"This serves to inform you that as of January 30, 2012, I took retirement from National Iranian Tanker Company's CEO," Souri, a prominent figure in the global shipping industry, said in a letter sent to Reuters on Tuesday.
"Although I shall no longer be directly involved with NITC management, I shall be assisting as an adviser and supporter."
Hamid Behbahani, formerly Iran's road and transportation minister, was named as NITC's new boss.
"My successor has demonstrated an outstanding level of competence in various management areas," Souri said.
NITC confirmed that Souri had retired, declining to comment further. Other NITC officials could not be reached for comment.
Behbahani, who was impeached by parliament for mismanagement in February 2011, is a close ally of Ahmadinejad.
"The interesting point is Souri's replacement ... It could be part of the power struggle in Iran. There is talk that he (Souri) was supported by the supreme leader (Ayatollah Ali Khamenei) and efforts to replace him some months ago failed," an oil analyst in Iran said.
"It is also possible that as hardline rivals blame Iran's isolation and sanctions on Ahmadinejad's policies, Souri wanted to retire when the company faces problems because of sanctions, to put all future responsibilities on the president's shoulders."
Supporters of tougher Iran sanctions measures are aiming to get NITC on a U.S. blacklist for what they say are links to the Iranian Revolutionary Guards Corps (IRGC). NITC has said it is a legitimate company and did not expect to be sanctioned.
The corps, which reports directly to Khamenei, has wide influence in Iran's economy and political system and the U.S. has targeted entities linked to it for sanctions.
Last week EU governments agreed to an immediate ban on all new contracts to import, buy or transport Iranian crude oil, a move to put pressure on Tehran's disputed nuclear program by shutting off its main source of foreign income.
Valerie Marcel, an associate fellow at Chatham House focusing on national oil companies in the Middle East, said the replacement by Behbahani fitted a pattern in recent years of professional technocrats being removed from positions related to the country's oil sector in favor of Ahmadinejad allies.
"(Ahmadinejad wants) to have a close ally in that strategic position of supervising or controlling tankers when there's an impending embargo on Iran's exports," Marcel said. "I think it's a sign that he wants to keep a close eye on those operations."
Souri, a graduate of Howard University in the United States, had worked in the private sector in the U.S. in the 1970s.
"He was not really aligned with anybody," said Manouchehr Takin, a petroleum analyst at the Centre for Global Energy Studies. "He was probably not in one political camp or another. He was more of a technocrat."
Souri's other roles included being chairman and managing director of the Islamic Republic of Iran Shipping Lines (IRISL) in the 1980s before joining NITC, NITC's website said.
IRISL has faced mounting U.S. and EU sanctions since 2008.
(Additional reporting by; Yeganeh Torbati in London; Editing by Anthony Barker)