The Kremlin requests the pleasure of your company at an all-European Communist Party conference - R.S.V.P.
''No thanks'' is the reply from Yugoslavs. They've signaled the Eurocommunists and other friendly parties they'll have nothing to do with such a meeting. Response from outside the Eastern bloc has been virtually nil. Yugoslavia's reasons for the rebuff: The Soviets haven't lived up to agreements made in 1976 about independent and separate ''roads to socialism'' and pledges of no more pretenses to a ''leading center'' (i.e., in the Kremlin).
''We see no point in another conference,'' a leading party official in Belgrade said, ''and we would not attend.''m