* Approval ends anxious wait for Brazil * New varieties fend off caterpillars, other threats * Monsanto shares up 4.8 percent early on Monday BRASILIA, June 10 (Reuters) - China has authorized three new varieties of genetically-modified soy from world No. 2 grower Brazil, including Monsanto Co's Intacta RR2, the South American country's agriculture ministry said on Monday, an endorsement critical to avoid trade disruption with Brazil's top soy customer. China's Agriculture Minister Han Changfu informed his Brazilian counterpart, Antonio Andrade, of the decision in person during a meeting in Beijing in which securing approval of the new seeds was top of Brazil's agenda. "This decision was anxiously awaited by Brazilian soy producers, given that the (seed) companies have only a few weeks to package and distribute the product in time for the seeding of the next harvest," Andrade said. The new GMO variety that Monsanto is ready to market in Brazil is designed to help fight outbreaks of Helicoverpa caterpillars that local producers have been struggling to control. Monsanto shares on the New York Stock Exchange were trading 4.8 percent higher on Monday. The ministry said the Chinese government also approved the GMO soy varieties of CV127 and Bayer's Liberty Link. China has been hosting a China-Latin America and Caribbean summit of agriculture ministers. Brazilian agriculture officials traveled to China in August last year to seek approval for new seed varieties and again last month when China's delays in approving the seed unnerved Brazil ahead of the planting period approaching. Soy is Brazil's single-biggest agricultural product by value. The country exported 5.6 million tonnes or $3 billion dollars worth of the protein-rich seed to China in April alone, accounting for about 78 percent of that months' soy exports. Soy is used mainly in livestock feed as a source of protein, as well as for human consumption. Brazilian soy planting over the past season has pulled neck-and-neck with the United States, currently the world's top producer. But Brazil has been dogged by problems in transport infrastructure, which has not kept pace with growth in the country's farm output.