MAASTRICHT, Netherlands (AP) _ PEN is expected to admit a new Soviet chapter this week in a move that would open the international writers' group to artists from the Soviet Union for the first time in 65 years.

Alexandre Blokh, PEN's international secretary, said in an interview on Sunday that he expects the organization's 53rd International Conference to admit the Soviet chapter in a vote Wednesday.

''They're certainly welcome and I think there will be no difficulty,'' Blokh said of the Soviet chapter, which was formed last year.

The PEN conference, a gathering of 300 novelists, poets, playwrights and other literary figures, opens in Maastricht on Monday.

Those attending will represent the 10,000 members of PEN, or Poets, Playwrights, Editors, Essayists and Novelists, a London-based group with about 60 chapters in its member nations.

In 1924, PEN turned down the Soviet Union's request to join the group, and since then the writers' group has consistently opposed Soviet membership because of the nation's persecution of writers and intellectuals.

The first official act of the new Soviet PEN chapter was to condemn the death threat Ayatollah Ruhollah Khomeini of Iran issued against British author Salman Rushdie, according to the Soviet newspaper Literaturnaya Gazeta.

If the Soviet chapter is approved, its members will have to sign the PEN charter, which condemns censorship and says ''free criticism of governments, administrations and institutions (is) imperative.''

The newspaper said members of the Soviet chapter include poets Yevgeny Yevtushenko and Andrei Voznesensky, novelists Anatoly Rybakov and Chengiz Aitmatov, historian Dmitri Likhachev, and playwright Mikhail Shatrov.

The approval of the Soviet chapter would be a significant breakthrough for Soviet writers, who were isolated from many international cultural groups until their nation's intellectual climate began to improve recently.

It would also be the latest indication that Western organizations approve of President Mikhail S. Gorbachev's policy of ''glasnost,'' or greater openness in Soviet cultural and intellectual affairs.

One obstacle to Soviet membership has been the large number of languages used in the country, Blokh said. Because PEN chapters are usually open to only one language group, the Soviets would be entitled to dozens of chapters and therefore be able to exert a disproportionate amount of influence, he said.

Under a compromise hammered out by the PEN leadership in Moscow last month, the Soviets would be allowed to open a maximum of five chapters, said Blokh.

Andrei Bitov, a novelist heading the six-man delegation of Soviet observers at the conference, told The Associated Press that Soviet PEN membership would be only ''one of the smaller changes'' made possible by Gorbachev.

''This organization was understood to be by those in power as reactionary (and) anti-Soviet,'' he said.

Even now, ''A lot of Soviet writers regard this only as an organization of prestige, not as an organization which will struggle against censorship (and for) the human rights of a writer,'' said Bitov, who himslef faced a six-year publication ban from 1979-85.