MOSCOW, MAY 24 -- Soviet lawmakers expressed surprise today at the government's unexplained dropping of a liberal emigration bill from its legislative agenda, despite earlier assurances that it would be approved in advance of next week's superpower summit.

The Kremlin's decision to delay passage of the bill -- which would give every Soviet citizen the right to hold a passport and travel freely for a period of five years -- effectively kills any chance that a new U.S.-Soviet trade agreement will be signed at the summit. The trade agreement would have lowered tariffs for Soviet goods in American markets and encouraged U.S. investment in the Soviet Union.

Nikolai Fyodorov, the chairman of a subcommittee that reviews new legislation, said that the decision to take the emigration law off the agenda was made behind closed doors by Kremlin leaders. He described it as "undemocratic" and "unconstitutional."

Hardly any members of the legislature spoke out against the proposed law when it was first debated earlier this year and Secretary of State James A. Baker III has said he was told last week in Moscow that the bill would be enacted May 31.

Western diplomats here speculated that the abrupt withdrawal of the bill may be linked to superpower maneuvering over Lithuania's bid for independence from Moscow. They said Kremlin leaders may have feared that Washington would hold the new trade agreement hostage to an ending of the Soviet Union's economic embargo of the rebel Baltic republic.

Opposition to the draft law has come mainly from Arab countries concerned that it could increase the number of Soviet Jews emigrating to Israel. Soviet sources said that Egyptian President Hosni Mubarak criticized the proposed relaxation on travel restrictions when he was in Moscow for talks with President Mikhail Gorbachev earlier this month.

Some Soviet officials have expressed fears of a brain drain of scientists and doctors lured by higher salaries in the West, but these arguments did not figure prominently in the debate.

Fyodorov, too, said the bill was scheduled to receive a final reading on May 31, the day that Gorbachev arrives in Washington for talks with President Bush. But it was absent from the latest version of the agenda that was distributed to deputies on Monday.

Staff reporter Don Oberdorfer added in Washington:

State Department spokesman Margaret Tutwiler said some Soviet officials have told the U.S. Embassy in Moscow that they believe the immigration law will be put back on the calendar for May 31. However, she said there has been no official clarification.

Last week in Moscow, Baker told senior Soviet officials that U.S. trade benefits for the Soviet Union were not politically viable in the United States while the Kremlin's squeeze on Lithuania continued, according to a senior administration official.