Russian President Vladimir Putin unveiled a government dominated by loyalists on Monday, tightening his grip on the economy and limiting Prime Minister Dmitry Medvedev’s ability to pursue his reform agenda.Igor Shuvalov, a powerful Putin ally, kept his post as first deputy prime minister in overall charge of economic policy and Anton Siluanov, a career bureaucrat, remained finance minister.Putin also consolidated his power over the security structures, with Anatoly Serdyukov staying on as defence minister, and kept faith with long-serving Foreign Minister Sergei Lavrov."Work will be difficult, given the concrete situation in the world economy ... there are very many uncertain factors,” Putin told a meeting of the new cabinet team in the Kremlin, where he sat at the head of the table with Medvedev on his right.Medvedev, 46, named premier after Putin returned to the Kremlin on May 7, has pledged to launch pro-growth policies and a privatisation drive to wean Russia’s $1.7 trillion economy off its dependence on oil.