NAO ME TOQUE, Brazil, Jan 26 (Reuters) - More than a thousand poor Brazilian farmers, joined by activists attending an anti-World Economic Forum summit, stormed a biotech plant owned by U.S. life sciences giant Monsanto (NYSE:MON - news), threatening on Friday to camp out indefinitely to protest genetically modified (GM) food.

Some 1,200 workers from settlements of the radical Landless Workers Movement (MST) in Brazil's southernmost state of Rio Grande do Sul invaded the plant just before midnight on Thursday, yanking out GM corn and soybeans crops at Monsanto's experimental farm.

``We're staying here indefinitely,'' said Solet Campolete, a local MST leader. ``We want to make a statement ... these seeds trick farmers and create dependency on seeds produced by a big multinational.''

The MST families took over the research center and warehouses, hanging hammocks and setting up mattresses and boxes of food. The protesters scrawled on the walls, ``The seed of death!'' and ``Monsanto is the end of farmers!''

Monsanto said on Friday it had requested that local authorities ``restore order'' at the unit.

``Monsanto regrets this incident in which it was a victim of an aggressive movement that puts the rights to freedom of movement and to private property at risk, but it affirms its confidence in democracy and a quick reaction by authorities to restore order,'' the company said in a statement.

ANTI-DAVOS FACTION JOINS PROTEST

Militant farmers from around the globe who are in Brazil for the World Social Forum, a rival meeting to the World Economic Forum in Davos, Switzerland, joined the protesters.

Jose Bove, the French farmer and leader of the Confederation Paysanne who catapulted to fame when he trashed his local McDonald's, took a four hour bus ride from the state capital of Porto Alegre to lend his support.

``Monsanto says transgenics require less pesticides and chemicals, but that's a lie. Transgenics increase dependence on those products,'' he said.

Monsanto says its lab-enhanced seeds increase productivity and reduce the use of agrochemicals among other benefits, but watchdog groups like Greenpeace have opposed the wide-scale use of biotechnology that they say has not been developed with sufficient environmental and health impact studies.

They also worry it will force farmers to become dependent on seeds produced in corporate laboratories rather than on those grown in the field.

Brazil is the only country in the Western Hemisphere that attempts to ban the commercial planting, importing or sale of GM food, but they do allow research.

Still, it has been an ongoing battle with the government often trying to reverse its position on GM and some farmers smuggling in GM seeds from neighboring Argentina. Industry insiders suspect up to a third of Rio Grande do Sul's soybean crop is GM.

The some 10,000 activists united in Porto Alegre for the ``Anti-Davos'' forum are expected to condemn GM food along with a wide range of what they say are neoliberal and capitalist policies that have deepened the divide between the rich and poor. MST families have led protests outside the Monsanto plant but it is the first time they invaded the facility.