BRUSSELS, Belgium (AP) _ European Commission President Romano Prodi recommended today that negotiations begin next year with six countries seeking future European Union membership, possibly as early as 2003.

Bulgaria, Latvia, Lithuania, Malta, Romania and Slovakia have fulfilled the criteria necessary to begin talks to join the EU, Prodi told the European Parliament in Brussels. Bulgaria and Romania, however, must meet certain further conditions, he said.

Talks are already underway with six other nations: Cyprus, Estonia, Slovenia, Poland, Hungary and the Czech Republic. The six countries recommended today had been relegated to a group on a slower path to membership.

Prodi said the negotiations should follow a ``differentiated'' approach, taking account of each candidate's progress.

``Rarely in the course of history does an opportunity like this present itself,'' Prodi told parliament. ``For the first time since the fall of the Roman Empire we have the opportunity to unite Europe. This time it will not be by force of arms but on the basis of shared ideals and agreed common rules.''

The Commission, the EU's executive arm, also decided that Turkey should now be considered a candidate, though it did not recommend opening negotiations at this time.

Prodi said whether the first accessions take place starting in Jan. 1, 2003 will depend entirely on the speed with which applicant countries can make progress on meeting membership criteria.

Countries wanting to join the EU must show they have stable political institutions guaranteeing democracy, the rule of law, human rights and the respect for and protection of minorities.

The economic criteria include having a functioning market economy and being able to withstand competitive pressure and market forces within the union.