(Bloomberg) -- Iran’s governor at OPEC, Hossein Kazempour Ardebili, went into a coma at a hospital in Tehran after suffering a brain hemorrhage, an official at the country’s oil ministry said.

Kazempour, who was first appointed as Iran’s governor to OPEC in 1985 and also served as the Islamic Republic’s ambassador to Japan, is considered by his peers as a formidable negotiator who is typically integral to forming Iran’s position, even standing in for Oil Minister Bijan Namdar Zanganeh during a gathering in 2018.

A vital adviser to Zanganeh, he helped shepherd the rehabilitation of Iran’s oil industry and its position within OPEC following the 2015 nuclear deal and the short-lived period of sanctions relief that spurred a major recovery in the country’s crude production. He also maintained relations with his Saudi counterparts at OPEC, even when ties were not smooth between the two regional powers.

An official at the oil ministry, who asked not to be identified because they are not authorized to be quoted by the media, said his hospitalization was not related to the coronavirus outbreak.

Kazempour has had ongoing heart problems and did not attend OPEC’s extraordinary meeting on March 5 because of the outbreak and the risks posed to his health by traveling, the oil ministry official said.

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