Oct. 27 (Bloomberg) -- OAO GMK Norilsk Nickel, Russia’s biggest mining company, climbed the most in more than two weeks on a report that its share buyback program may not need antitrust approval.

The shares rose as much as 3.7 percent before trimming gains to trade up 2.8 percent at 6,407 rubles at 1:17 p.m.

The buyback program won’t need antitrust approval if Norilsk’s overseas unit, which is carrying it out, purchases less than 10 percent of the nickel-mining company’s shares, RIA Novosti said, citing Federal Anti-Monopoly Service Chief Igor Artemyev.

Norilsk plans to purchase about 7.7 percent of its shares in the $4.5 billion buyback, which closes tomorrow.

The watchdog considered challenging the deal unless Russia’s state commission on foreign investment, headed by Prime Minister Vladimir Putin, approved it, the Kommersant newspaper said last week, citing unidentified people.

A review of the buyback “isn’t on the agenda,” Putin’s spokesman, Dmitry Peskov, said by phone Oct. 24.

--Editors: Torrey Clark, Alex Nicholson

To contact the reporter on this story: Yuliya Fedorinova in Moscow at yfedorinova@bloomberg.net

To contact the editor responsible for this story: Torrey Clark at tclark8@bloomberg.net