REFILE-ANALYSIS-Bolivian vote could spark grave political crisis

(Fixes typo in first paragraph)

By Carlos Alberto Quiroga

LA PAZ, April 23 (Reuters) - An upcoming autonomy referendum for Bolivia's richest province may push the South American nation on a path toward political disintegration, analysts said.

The May 4 vote in Santa Cruz province, which has rich farm land and natural gas reserves, could make it impossible for leftist President Evo Morales to govern, they said.

"Bolivia's existence is at risk," said Andres Soliz, an analyst and former energy minister under Morales.

Morales's conservative opponents have been pushing autonomy for the better-off lowlands. The president's power base is concentrated in the poor, traditionally Indian highlands.

With opponents boycotting the vote, the autonomy resolution is expected to win landslide approval.

"What's coming is a Morales who cannot govern the whole country effectively and an opposition that is strong only in some regions, without a national presence," said political analyst Cesar Rojas.

He warned of a "general breakdown" in the landlocked Andean country that is South America's poorest.