Citing unidentified sources in both companies, the Vedomosti newspaper reported Wednesday that Gazprom had begun talks to acquire the 57.5 percent stake in Sibneft owned by Abramovich's Millhouse Capital. Neither company would comment on the reports.
Analysts said a Gazprom takeover would advance the Kremlin goal of bringing the crucial oil and gas sector under tighter state control.
"There is a change of guard on the commanding heights of the economy," Michael Heath, a political analyst at Aton Capital in Moscow, told Dow Jones Newswires. "In future, there will be a new elite of state officials who will be running the oil and gas industry."
Gazprom and state-controlled oil giant Rosneft continue to jockey for position following the breakup of the Yukos oil giant. The two companies had been expected to merge to create an oil and gas behemoth, but disputes between rival Kremlin-affiliated camps over control of a coveted Yukos subsidiary appear to have waylaid the merger, at least for now.
The Wall Street Journal reported Thursday that Rosneft also was conducting talks to acquire Sibneft. The reports could not be immediately confirmed.
Foreign investors are eagerly awaiting a decision by the Russian government to let Gazprom offer its lucrative shares on open markets.
Abramovich is best known outside of Russia as the owner of Britain's Chelsea soccer club.
On the photo: Roman Abramovich