ST. PETERSBURG (AP) - Prime Minister Vladimir Putin unveiled an exhibit from the art collection of a renowned Russian cellist Monday, a ceremony that reflected his continuing political influence even after stepping down as president.

Putin opened the collection of the late cellist Mstislav Rostropovich and his widow Galina Vishnevskaya at a majestic imperial-era palace near St. Petersburg, hours after presenting his new Cabinet.

Russia's television stations covered Putin's speeches in Moscow and St. Petersburg, and the reports gave some indication as to what Putin's new responsibilities will be.

Medvedev was inaugurated Wednesday as the new president of Russia, while Putin, who enjoys tremendous popularity, was nominated as the prime minister the next day.

Hours after announcing his Cabinet, Putin joined Vishnevskaya - a Bolshoi Opera soprano - in touring the exhibit of the paintings, home furnishings and other objects on public display for the first time in the Konstantin Palace.

The opulent palace overlooking the Gulf of Finland was recently restored and Putin - a St. Petersburg native - has taken to using it for hosting grand events, such as a summit of the Group of Eight leading industrialized nations in July 2006.

"It wasn't by accident that the Konstantin Palace was chosen as the new home for the collection. It has been returned and restored practically from the ruins and today it is a symbol of the revival of our country, representing the continuity of our historic, spiritual and cultural traditions," he said.

Rostropovich, one of the world's most popular classical musicians, and his wife assembled the collection of Russian art in the decades after they emigrated from the Soviet Union and kept the pieces at their homes abroad.

After Rostropovich's death in April 2007, Vishnevskaya decided to put the collection up for auction at Sotheby's in London.

But right before the sale, billionaire metals tycoon Alisher Usmanov bought the collection to donate it to the Russian state.