So far, the most the other nine have been willing to offer Greek and Italian farmers is about $70 million in special aid next year.

At one point, Mr. Papandreou angrily walked out of the meeting, which dragged on late into the evening as a result of the Greek demands.

Greece bases its demand for $5 billion in agricultural aid for southern European farmers on very generous proposals suggested earlier this year by the Common Market's executive commission in Brussels. Program Called Too Costly

But leaders of other Common Market nations say they never agreed to this ''integrated Mediterranean program,'' as it is called. They said it was too costly at a time when the Market countries were seeking to cut back spending on farm subsidies in order to devote more resources to industrial development and scientific research, which they see as more relevant to the task of reducing Europe's high unemployment.

Since Greece joined the Common Market in 1980, Prime Minister Papandreou has regularly adopted maverick positions, annoying other members by refusing to criticize the Soviet Union over the shooting down of a South Korean airliner last year and to condemn martial law in Poland.

Finally, the other nine Common Market leaders decided to complete their entry negotiations with Spain and Portugal in the next few weeks on the basis of the proposals they have now agreed on among themselves. They will then try to resolve their disagreement with Greece by the time of the next Common Market meeting in March.

But earlier hopes that Spanish and Portuguese entry terms could be effectively settled by the start of next year have now been scuttled, officials say. And a new question mark hovers over the Common Market's future enlargement. Hope for Smoother Period