RABAT, May 28 (Reuter) - Morocco warned the European Union that its failure to end a Spanish trade war against Morocco in an escalating fishing row could endanger Morocco-EU relations, newspapers said on Saturday.

They said Prime Minister Abdellatif Filali summoned EU's envoy in Rabat, Marc Pierini, to express displeasure at what he described as the EU's complacency in the face of blockade of Moroccan goods transiting Spain.

"Mr Filali told the EU envoy of the grave consequences for Moroccan-EU relations and the Spanish fishermen responsible for these acts of obstruction and harassment will be the first victims," the papers said, quoting a statement by his office.

The statement said he told Pierini that Morocco was "disappointed that the EU's reaction had been confined to verbal denunciation of Spain's behaviour but had taken no concretemeasures to put an end to these unacceptable acts."

Spanish fishermen in the southern port of Algeciras imposed a blockade of Moroccan goods after an EU-Moroccan fisheries agreement, which benefits mainly Spain, expired at the end of April. They said on Friday they would ease the blockade on Moroccan imports but would not allow any fish through.

Morocco told 730 EU vessels, of which 650 are Spanish, to quit its Atlantic waters until a new three-year fishing deal, the EU's most important external fisheries accord, is reached.

EU Fisheries Commissioner Emma Bonino on Friday accused Spanish fishermen of vandalism after they destroyed a cargo of Moroccan shrimp and said this would not help the talks due to resume in Rabat on June 1.

Morocco wants strict new fishing quotas to preserve stocks and is demanding that catches be landed at its ports. The EU agrees to the principle of the cuts but not their extent.

Morocco's Fisheries Minister Mustapha Sahel told parliament the pressure by Spain would have no influence over Morocco's negotiating position.

He also said Morocco had started urgent contacts with France to establish new sea links to bypass southern Spain, currently the main transit point for Moroccan exports to EU countries.