The final week of history's most far-reaching trade talks opened Monday with no breakthrough in sight for a bitter dispute over farm subsidies between Europe and the United States.

"No world trade negotiation has ever had the scope or intensity as this one. The well-being of millions of people are at stake this week," Belgian Prime Minister Wilfried Martens told trade ministers from 107 countries at the opening session.The trade-liberalization talks under the General Agreement on Tariffs and Trade, which began at anUruguayan resort in 1986, are supposed to conclude on Friday.

Top officials say, however, the GATT talks will collapse unless the United States and the 12-nation European Community quickly reach an agreement over agriculture subsidies. The EC has resisted U.S. calls for deep cuts in farm supports.

An estimated 30,000 farmers - mostly from Europe but a few from Japan, Korea, Africa and North America - marched through downtown Brussels to protest against reduced farm subsidies.

"Do not spoil the future of agriculture and rural areas," read one sign, which cleverly linked GATT's initials with the French word "gater," which means "to spoil."

In his opening remarks, the EC trade commissioner strongly defended the Community's position on farm subsidies, saying it constituted a "perfectly valid basis" for reaching an agreement.

U.S. officials sharply disagreed, saying developing countries that produce food cheaply will walk out of the talks unless the EC agrees to steep cuts in price-distorting farm supports.

A nasty trade war is feared if the GATT talks fail. World trade totaled more than $3 trillion last year.

GATT, created in 1947 to reduce tariffs and spur world trade, now only covers trade in merchandise.

The current round of GATT talks, named the Uruguay Round after its birthplace, was designed to also bring agriculture, services, investment and intellectual property rights under world trade rules.