Kazakh president declared Leader of the Nation

Kazakhstan's President Nursultan Nazarbayev speaks at the opening of the Kazakhstan Investment Summit in Almaty June 3, 2010.

ASTANA (Reuters) - President Nursultan Nazarbayev was declared Kazakhstan's Leader of the Nation on Tuesday, which could signal the start of his gradual departure from the political scene in the oil-producing Central Asian nation.

The law grants Nazarbayev the right to shape policy after retirement and immunity from prosecution. He had earlier rejected the draft but has not formally vetoed it.

Nazarbayev, 69, has been in power since 1989 but has no clear successor. The uncertainty has worried investors who have poured more than $100 billion into the vast Caspian nation since its independence from the Soviet Union in 1991.

"It's a signal from the president to political players: 'Folks, don't worry about the successor. The mechanism of preparing a successor has been launched'," said Dosym Satpayev, a political analyst.

"This law offers a framework for him to leave and hand over power. There was no such framework before."

The state Kazakhstan Pravda newspaper said the bill had officially come into law after being signed by the prime minister and the speakers of both houses of parliament.

"The law is effective from the day of its official publication," stated the decree, published on Tuesday.

Kazakhstan has never held an election judged free and fair by Western observers and the Kazakh leader has tolerated little dissent in the country of 16 million during his years in power.

Nazarbayev's son-in-law Timur Kulibayev, as well as Kasym-Zhomart Tokayev, speaker of the upper house, and a host of other politicians have been tipped as potential successors but the subject is taboo and officials never comment on it.

The Kazakh leader's current term expires in 2012 but he can run for an indefinite number of terms under a law introduced in 2007. He has not publicly said if he plans to run again.

Earlier in June, Nazarbayev cited Kazakhstan's role as chair of the Organization for Security and Cooperation in Europe (OSCE) -- a security and democracy watchdog -- as one of his main reasons for rejecting the bill.

However he never officially vetoed the draft, leaving a legal loophole for the bill to come into force.

The new law gives Nazarbayev control over government policy after leaving the presidency as well as immunity from criminal prosecution for any actions taken while in office. It also protects all assets of the president and his family.

(Writing by Maria Golovnina)