WASHINGTON--President Bush announced yesterday that he will hold a shipboard summit in the Mediterranean with Soviet President Mikhail S. Gorbachev December 2 and 3 "to put up our feet and talk" informally prior to a full-blown superpower meeting next year.

Bush described the weekend meeting as an open-ended discussion with no fixed agenda. He said neither he nor Gorbachev "anticipate that substantial decisions or agreements will emerge" no arms control or other matters.

The talks will take place on U.S. and Soviet naval ships on alternate days. The precise location was not announced, but a site off Italy appeared likely since Gorbachev is to visit there from November 29 to December 1.

Bush acknowledged he originally had opposed the concept of a getacquainted meeting, favoring instead a well-planned meeting with assurances of concrete results.

However, he decided that with dramatic democratic changes sweeping across Eastern Europe, the leaders of the two superpowers "should deepen our understanding" of each other.

"I don't want to have two gigantic ships pass in the night because of failed communication," Bush said. "I just didn't want to--in this time of dynamic change--miss something, something that I might get better first-hand from Mr. Gorbachev."

The president said he expected "a lot of discussion" about Eastern Europe.

Bush's announcement drew bipartisan applause on Capitol Hill, although Senate Majority Leader George Mitchell (D-Maine) said he was not about to rescind his criticism that the president's policies toward the blossoming of democracy in Eastern Europe have been too "timid."

The summit was jointly announced in Washington and in Moscow, where Soviet Foreign Minister Eduard Shevardnadze said the talks between the two leaders were "aimed at allowing them to know each other better" and would "contribute to broadening the changes taking place in the Soviet-American relationship."

Much of the planning appeared still to be done.

White House Chief of Staff John Sununu, when asked what country Bush would use as the staging area for the talks, said, "We don't know yet." However, sources suggested that Naples, Italy, a major seaport, was the most likely area.

The sources, insisting on anonymity, also said the most likely U.S. ship for the talks was the cruiser Belknap, the 547-foot long, missile-armed flagship of the Sixth Fleet, based in the Mediterranean. There was speculation Bush would make the ship his headquarters and spend the night there.

Officials said they did not know if first ladies Barbara Bush and Raisa Gorbachev would accompany their husbands.

Bush said he decided to meet on a ship so "we can do it without too much fanfare...where there's a relatively few number of people, not a lot of crush of bodies out there and a chance to put our feet up and talk...I think it's easy logistically for both sides."

It will not be the first shipboard summit.

In August 1941, five months before the United States entered World War II, President Franklin D. Roosevelt '04 met with British Prime Minister Winston Churchill aboard a battleship offNewfoundland, Canada, and proclaimed an AtlanticCharter providing for freedom of the seas andleading to the arming of merchant ships.

It will be Bush's first meeting as presidentwith Gorbachev, although he participated in talksin Washington and New York with the Soviet leaderwhile serving as Ronald Reagan's vice president.

Bush and Gorbachev have agreed to meet in latespring or early summer to deal with major issues,and Bush said yesterday he still hopes to be ableto sign a treaty then to reduce strategic nuclearweapons.

The December meeting gives Bush a defenseagainst Democratic charges that he has been slowto respond to initiatives from Gorbachev and tothe striking changes under way in the Soviet Unionand elsewhere in Eastern Europe. Gorbachev,meanwhile, is under pressure to demonstrate thathis program of economic restructuring can improvethe lives of ordinary Soviet citizens