Finance Minister Alexei Kudrin said the first meeting would be held on February 10-11 in Moscow, with a further session in late May or early June in St. Petersburg - the venue of Russia's first full G8 summit in July.
The announcement finesses what had become an awkward diplomatic problem: Former President Boris Yeltsin was first invited to a Group of Seven summit in 1997 and Russia won full political membership of an enlarged G8 in 2002.
It assumes the rotating presidency of this body in 2006.
But Moscow remains an onlooker when finance ministers from the United States, Japan, Germany, Britain, France, Italy and Canada discuss issues like exchange rates under the close scrutiny of international investors.
A senior official played down the importance of the new format, saying Russia had become increasingly involved in Group initiatives over the years such as ensuring stable world energy supplies.
Economists said greater involvement of the largest of the emerging economies - known collectively as the BRIC nations - would help boost the relevance of the G7 finance forum, which has grown stale in recent years.