BRUSSELS, April 23 (Reuter) - Barely a week after the end of a fishing dispute with Canada, the European Union's Fisheries Commissioner Emma Bonino will make a last-minute attempt on Monday to reach a new fish accord with Morocco.

EU and Moroccan negotiators remain far apart after two rounds of talks. Unless a deal is struck by the end of the month, 650 mainly Spanish and Portuguese boats will be barred from Morocco's rich fishing grounds.

At stake is the EU's most important external fisheries agreement, providing a livelihood for 28,000 fishermen and fish processors in southern Spain, the Canary Islands and Portugal.

"Things are extremely difficult...the Moroccans are demanding far more than we can give," a European Commission spokesman said.

Bonino will meet Moroccan Prime Minister Abdellatif Filali and Fisheries Minister Mustapha Sahel in Rabat on Monday and a third round of technical talks is also due to begin.

Morocco, like Canada, wants to protect dwindling fish stocks and to guarantee local fishermen future supplies.

It hopes to halve the number of EU fishing vessels and to cut quotas by between 30 and 65 percent depending on the type of fish, including sardines, tuna, squid and shrimp.

The EU's dispute with Canada revolved around Ottawa's desire to protect Greenland halibut (turbot) stocks, which straddle national and international zones, but Morocco is trying to cut fishing only inside its 200-mile limit.

"Morocco is acting entirely within international law," an EU source said.

In exchange for fishing rights, the EU paid Morocco about $130 million a year under the current agreement.

The first EU-Morocco fisheries accord was concluded in 1988. The latest, signed in 1992, is due to end on April 30.