The prime minister of Kazakhstan has resigned after leading the oil-rich Central Asian nation for five years and shepherding its economy through the global financial crisis. Karim Masimov's resignation was accepted Monday by presidential decree. Masimov was the longest-serving head of government in the former Soviet nation's history and was widely respected in the international investor community. Real power in Kazakhstan is held by President, but Masimov has been seen as an influential and competent steward of economic affairs. His resignation had been expected, though the reasons behind it are unclear. Recent reports have linked Masimov with an appointment to a senior post in the presidential administration.