"This is a clear signal to the United States not to put too much pressure on Russia in WTO talks otherwise many lucrative contracts and privileges could go to the Europeans," Yaroslav Lissovolik, an analyst from the Deutsche UFG investment house, told Vedomosti.
In December, Vedomosti had said Aeroflot was considering buying 22 Boeing 787s, known as Dreamliners.
But on Saturday it reported an anonymous official in Russia's presidential administration as saying that Aeroflot's board of directors had decided "last month that Aeroflot should buy the Airbus-350 liners".
Vedomosti estimated the cost of an Airbus deal at $3billion.
But Aeroflot said it was too early to talk about the results of the tender since no contract had been signed.
"The results of the tender will be announced when we sign the contract. We haven't done that yet," a spokeswoman Irina said.
"For some time, Boeing was preferred. Now we are looking at offers from Airbus. We haven't chosen the planes yet."
The Russian government holds a 51% stake in Aeroflot.
Vedomosti said Aeroflot had delayed announcing its decision after an Airbus A320 passenger jet belonging to Armenia's Armavia airline crashed into the Black Sea on Wednesday, killing all 113 people on board.
Moscow has signed an agreement with the European Union to pave the way for it to join the WTO, but it has yet to clinch such a deal with the US.