WORLD : Baker Tackles Summit Obstacles

MOSCOW — Secretary of State James A. Baker III, backed by three dozen advisers, arrived in the Soviet capital today to try to overcome deep differences over missile reductions that could impede success at the Washington summit.

Soviet President Mikhail S. Gorbachev is due to see President Bush in only two weeks, and senior Baker aides said on the flight to Moscow that at least four key issues were unresolved.

Already, the two sides have decided to resume negotiations in Geneva right after Baker concludes his visit Saturday, take a break for the May 30-June 3 summit and then work through the summer.

This suggests there is little hope that Baker, in his talks with Gorbachev and Foreign Minister Eduard A. Shevardnadze, can settle all the remaining issues in time for a summit declaration.