The 10 European Community member states have decided against issuing a statement of support for beleaguered Palestine Liberation Organization Chairman Yasser Arafat.

The decision was made during meetings to work out a joint community foreign policy here this week.

Informed sources here said that Greece, which is chairing the meetings, strongly favored the proposal to issue a statement backing Arafat. But, according to the sources, there was active opposition from other member states such as Britain and West Germany, who favored staying out of internal Palestinian disputes. There was also concern about having the community back Arafat in the event that he emerges as the loser in the present PLO quarrel.

News agencies reported these other developments:

The Soviet Union Wednesday urged dissidents and loyalists in the Palestine Liberation Organization to open a "dialogue" to end the two-month-old rebellion against the leadership of PLO Chairman Arafat, United Press International reported from Moscow.

The advice came during the second meeting in two days between Soviet Foreign Minister Andrei Gromyko and Farouk Kaddoumi, political chief of the PLO, according to the Soviet news agency Tass.

The Tass dispatch indicated Soviet support for both the PLO and Arafat but stopped short of openly backing the beleaguered guerrilla chieftain.

In Amman, Jordan, Aziz Omar Shennib, who defected Tuesday as Libyan ambassador to Jordan, said that Libyan leader Muammar Qaddafi personally ordered him to organize the assassination of Jordan's King Hussein, Agence France-Presse reported Wednesday.

Shennib told AFP that "Col. Qaddafi ordered me to Tripoli to inform me that a repugnant terrorist action against King Hussein was going to take place in Jordan . . . . SAM surface-to-air missiles were going to be placed near the airports at Amman and Aqaba, southern Jordan, and they were to be fired after the royal plane had taken off."