President Tito, the sole surviving founder of nonalignment, has launched a worldwide diplomatic campaign to keep the movement independent of the two big power blocs.

The 87-year-old Yugoslav leader has devoted a remarkable burst of political energy over the last few months to salvaging what he regards as one of the principal pillars of Yugoslavia's hard-won independence from the Soviet Union. For a variety of reasons, however, the signs so far are that he is meeting with only limited success.

Senior Yugoslav officials have made clear that they believe the Kremlin is attempting to subvert the 86-nation movement from within through the disruptive activities of proxy nonaligned states such as Vietnam and Cuba. Also worrying Tito are moves by some Arab countries led by Iraq and Syria to deprive Egypt of its nonaligned status in retaliation for the conclusion of a peace agreement with Israel.

The Yugoslavs fear that attempt, though unlikely to succeed, could irreparably damage the nonaligned movement.

A skirmish between contending forces has occurred at a ministerial-level coordination committee session in Sri Lanka that began Wednesday. The meeting has been called to prepare for a summit meeting of nonaligned heads of government in Havana, scheduled for September.

The choice of Havana for the summit conference has caused grave misgivings among some other nonaligned states who fear an attempt to foist pro-Soviet policies on the movement. Some countries, including Somalia and Zaire, have indicated they will boycott the Havana meeting or seek its postponement.

Yugoslavia's diplomatic offensive has been led by Tito, who has visited seven key nonaligned countries in the last five months and has sent personal envoys on missions to Africa, Asia and Latin America. In addition, non-alignment was one of the main subjects Tito brought up during his meeting with Soviet President Leonid Brezhnev in Moscow last month.

According to Yugoslav sources, Brezhnev showed little sympathy to appeals for the Soviet Union to exercise a moderating unfluence over its allies within the nonaligned movement. Instead, he accused Yugoslavia of conducting an unjustified campaign against Cuba and Vietnam and repeated longstanding for Yugoslav independence.

A senior Western diplomat in Belgrade commented: "Tito's problem is that he has little to offer the Soviets in return, without sacrificing his own autonomy. Given their present mood, the Russians have little reason to want to rein in Cuba. They're quite happy watching Tito stew in his own juice."

Soviet intransigence apart, Tito faces major hurdles in urging the nonaligned movement to strengthen its independence and unity.

The movement is a collection of very diverse states, many at logger-heads with each other. Included in the nonaligned movement (which sometimes votes as a bloc at the U.N. General Assembly) are states as ideologically diverse as Argentina and Saudin Arabia on the right and Angola and Libya on the left with the Central African Empire and Equatorial Guinea on the maverick fringe.

At the last count there were at least half a dozen major rows brewing simultaneously within the movement, including armed conflicts involving Vietnam and Cambodia, Ethiopia and Somalia, and Tanzanian troops leading the drive to oust Idi Amin in Uganda.

It is hardly surprising, therefore, that few other nonaligned members share Yugoslavia's obsession with the Kremlin, which stems from Yugoslavia's experience of being the first communist country to break away from the Soviet Bloc. Other non-aligned countries have different pre-occupations nearer home.

One reason is that the first non-aligned summit coincided with a reconciliation between Yugoslavia and the Soviet Union.

Today Yogoslavia-Soviet relations are quite strained but the Yugoslavs have not been able to update the slogans of the movement accordingly.