MOSCOW: Ravil Maganov, the chairman of Russia's second-largest oil producer Lukoil (LKOH.MM), died on Thursday after falling from a hospital window in Moscow. With this, Maganov became the latest addition to the series of Russian businessmen who have met with sudden unexplained deaths. Ravil Maganov has been the head of the company since its inception in 1993.

Sources have confirmed reports by several Russian media that the 67-year-old had plunged to his death. However, the circumstances surrounding his fall were unclear.

Lukoil said in a statement that Maganov had "passed away following a serious illness". "Lukoil's many thousands of employees mourn deeply for this grievous loss and express their sincere condolences to Ravil Maganov's family," it said.

Meanwhile, people close to Maganov said that they believed it was highly unlikely he had committed suicide.

Another source close to the company said there was a belief inside Lukoil management that Maganov had killed himself, but he had not seen evidence or documents to support that.

Several other senior executives with ties to Russia's energy industry have died suddenly in unclear circumstances in the past few months.