The official spokesman for Gazprom-Media refused to comment, however, and the company said in a written statement that it will not reveal the value of the deal.
Gazprom bought just over 50 percent of "Izvestiya" shares from Interros, a vast holding company belonging to oligarch Vladimir Potanin.
A number of media professionals have voiced deep concern over the Gazprom takeover of Izvestia, a respected daily considered to be one of Russia's most objective, high-brow publications.
Many view the takeover as the latest move in the Kremlin's campaign to silence news organizations critical of its policy.
"I am very much afraid that there will be attempts to cleanse 'Izvestiya' and make it as loyal as everything that belongs to this huge holding, Gazprom-Media, to make media outlets obedient," said Manana Aslamasyan, the vice president of Russia's National Association of Television and Radio Broadcasters.
Mikhail Kozhokin, a former editor-in-chief of "Izvestiya," said both sides might well have had a financial interest in the deal. But he also described Gazprom's purchase of "Izvestiya" as an attempt to muzzle independent media.
"In Russia, business is interknitted with politics, just as business decisions and political processes are interknitted in the media sphere," Kozhokin said. "Media outlets increasingly find themselves under the control, or the strong influence, of the government through a variety of methods."
In 2001, after a trial of strength between the Kremlin and the exiled media baron Vladimir Gusinsky, Gazprom took control of NTV, a major television station overtly critical of President Vladimir Putin's regime.
In the official statement, the head of Gazprom-Media remained ambiguous about possible changes in "Izvestiya"'s editorial staff. He said his company needed to carry out a detailed analysis of the situation within the paper before deciding whether to introduce such changes.
Many experts fear "Izvestiya" will meet the same fate as NTV, which was deserted by a number of prominent journalists after the Gazprom takeover.
The television station has since considerably toned down its criticism of the government.
Igor Yakovenko, the general secretary of the Russian Union of Journalists, accused Gazprom of "killing" NTV and called "Izvestiya"'s change of hands "bad news" for the daily.
He said "Izvestiya" was well managed by Prof Media, the publishing arm of Interros, and predicted that Gazprom would run the prestigious daily into the ground.
"When 'Izvestiya' belonged to the Prof-Media holding -- although this holding is extremely loyal to the authorities -- these people did business and therefore looked for ways to keep 'Izvestiya' running and make it truly interesting," Yakovenko said. "[The takeover] will lead to the destruction of one of Russia's oldest and best media brands."
The takeover has also prompted speculation that Potanin is selling "Izvestiya" to Gazprom as a gesture of goodwill toward the Kremlin.
Another oligarch, Mikhail Khodorkovskii, was sentenced to nine years of prison on 31 May for fraud and tax evasion.
Potanin is viewed as businessman particularly careful not to anger the Kremlin.
Following the Beslan hostage tragedy in September, "Izvestiya" Editor-in-Chief Raf Shakirov resigned amid rumors that Potanin had asked him to leave for fear the Kremlin would be riled by the explicit photographs of the massacre published by "Izvestiya."