In an unsourced report, La Gazzetta dello Sport said Fininvest owner, Prime Minister Silvio Berlusconi, had discussed the sale of a 25-30 percent stake in the club with Russian prime minister Vladimir Putin during his visit to Italy last month.
The minority stake in Milan would be valued at 150 million to 180 million euros, the newspaper said.
On Friday, Italy's Libero daily said Gazprom was considering a 30 percent stake in Berlusconi's holding company Fininvest, who called the report "totally groundless".
"We strongly denied a report on Friday. There is nothing to add," a Fininvest spokesman said on Tuesday when asked about the Gazzetta story on Gazprom being interested in Milan.
Gazprom also rejected the report. "We deny it," said spokesman Sergei Kupriyanov.
Analysts often describe Gazprom as the Kremlin's most efficient foreign policy weapon and some of the company's most important decisions must cleared by the Kremlin or Putin.
Milan have bought few new players despite selling Kaka to Real Madrid for 67 million euros last year, and were eclipsed last term by neighbours Inter who won the treble.
Milan are also looking for a manager with the inexperienced Leonardo having left by mutual consent this month after they finished a distant 12 points behind Jose Mourinho's Inter in third place following the Brazilian's one season in charge.
Former Cagliari boss Massimiliano Allegri is in the running to take over from Leonardo but no decision has been taken, chief executive Adriano Galliani said on Monday.
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