Nursultan Nazarbayev is stepping down as president of Kazakhstan, effective March 20, after nearly 30 years of ruling the oil-rich nation, The Associated Press reported.

Nazarbayev, who was first elected in 1991, announced his resignation in a televised address without citing a specific reason for his decision, according to the report.

The 78-year-old leader, however, is expected to keep wielding power and will remain chairman of Kazakhstan's Security Council and head of the ruling Nur Otan party.

Nazarbayev said Kassym-Jomart Tokayev, the speaker of the upper house and a former prime minister, will serve as interim president until the next elections, in line with the constitution.

Nazarbayev's resignation and the succession plan reduce the transition risk, which is considered by many investors as the largest risk in the country, analysts at ING Research said. "For now, we expect a muted market reaction as the preparations point to ongoing political stability," the analysts said in a research note.