By Sergio Burgoa

ORURO, Bolivia, Dec 9 (Reuters) - An assembly boycotted by the rightist opposition to Bolivian President Evo Morales approved most of a controversial new constitution he supports during an all-night session guarded by miners and peasant farmers.

The assembly dominated by delegates from Morales' Movement Toward Socialism, or MAS, party, approved changes that would allow two consecutive five-year terms for presidents, greater state control of the economy, and more autonomy for provinces and indigenous communities.

"We're coming to a happy ending, we're managing to approve the new constitution the Bolivian people are asking for," said Roman Loayza, head of the MAS delegates in the assembly after 13 hours of voting in a university auditorium in Oruro, 140 miles (230 km) south of La Paz. More than 400 changes were approved.

But several steps are necessary before the constitution can be enacted. First, a nationwide referendum is needed on one remaining article. Then, the assembly will vote on the entire text. Finally, another nationwide referendum is required on the full constitution.

The assembly was moved to Oruro after three people were killed two weeks ago in violent protests against the process in Sucre, where it had been meeting for months.

As the assembly voted on Saturday night and Sunday morning miners and peasant farmers loyal to Morales guarded the university auditorium where the session was being held, exploding small dynamite charges occasionally to intimidate any potential anti-assembly protesters.

OPPOSITION BOYCOTT

The assembly also approved articles requiring election rather than appointment of top judges, and transforming the voting mechanism for the upper house of Congress, which is currently controlled by the opposition.

Bolivia's poor, indigenous majority has clamored for a new constitution and forming one was a key campaign promise of Morales, the country's first president of indigenous descent.

But the overhaul of the constitution has widened the rift between the mountainous, largely poor and indigenous part of the country that backs Morales, and the relatively wealthy western lowlands, where the opposition has greater force.

Of the assembly's 255 delegates more than one third boycotted Saturday's session, including Bolivia's two biggest right and center-right parties, who decry the process as a Morales power grab.

The assembly left one article -- a technical definition of unproductive land holdings -- for a nationwide referendum, apparently in a political maneuver that will make it easier to get the entire text ratified in the assembly early next year.

Morales is an ally of Venezuela's Hugo Chavez, whose own constitutional reform project was defeated narrowly in a referendum last weekend. Another ideological ally, Ecuador's Rafael Correa, is also pushing changes to his country's constitution. (Writing by Fiona Ortiz, editing by Jackie Frank) (e-mail: buenosaires.newsroom@reuters.com; Reuters Messaging: fiona.ortiz.reuters.com@reuters.net; telephone: +54 11 4318 0618))

AlertNet news is provided by