THE UNION OF THE SIX COMMON MARKET CAPITALS IS NOW HOLDING A CONGRESS IN BRUSSELS. AND TODAY (FRIDAY) THE MAYORS OF BRUSSELS, BONN, PARIS, ROME, AMSTERDAM AND LUXEMBOURG WERE RECEIVED BY THE PRESIDENT OF THE COMMON MARKET EXECUTIVE, MR WALTER HALLSTEIN.

FRENCH OFFICIALS IN THE BELGIAN CAPITAL WERE OPTIMISTIC TODAY THAT THE COMMON MARKET'S COUNCIL OF MINISTERS -- MEETING NEXT WEEK -- WILL BE ABLE TO AGREE ON THE OPENING OF EXPLORATORY TALKS WITH SPAIN.

THE COUNCIL IS DUE TO DISCUSS TWO ALTERNATIVE DRAFT REPLIES DRAWN UP BY M. SPAAK, BELGIUM'S FOREIGN MINISTER. THE FIRST SAYS SPAIN CANNOT HOPE FOR ASSOCIATION WITH THE COMMON MARKET BECAUSE ASSOCIATION OF A EUROPEAN COUNTRY MUST BE CONSIDERED A STEP ON THE WAY TO FULL MEMBERSHIP,WHICH IS EXCLUDED BECAUSE OF SPAIN'S POLITICAL REGIME.

BUT THE SECOND DRAFT STATES THAT THE 'SIX' WOULD BE WILLING TO OPEN EXPLORATORY TALKS ON TRADE QUESTIONS ONLY.

FRANCE IS IN FAVOUR OF OPENING EXPLORATORY TALKS WITHOUT SPECIFYING THE TYRE OF SOLUTION WHICH WILL EVENTUALLY BE DECIDED ON.

FRESH DELAYS IN IMPLEMENTATION OF THE EUROPEAN COMMON MARKET'S AGRICULTURAL POLICY AND THE "KENNEDY ROUND" OF GATT TARRIFF- CUTTING NEGOTIATIONS WERE REPORTED TODAY. THE "SIX" COMMON DAIRY, MEAT AND RICE POLICY -- AGREED UPON AT THE COUNCIL OF MINISTERS MARATHON SESSION LAST DECEMBER -- WILL NOT NOW COME INTO EFFECT AS SCHEDULED ON JULY ONE.