CHICAGO (AP) _ Winds gusting up to 56 mph blasted gravel and other debris into the world's tallest building Monday, and 90 of the Sears Tower's windows cracked or shattered, officials said.

There were no reports of injuries from falling glass, said police and officials of Sears, Roebuck and Co., which has its corporate headquarters in the building.

Police cordononed off the streets surrounding the 110-story building during the working rush hour, and planned to keep one closed as a precaution throughout the day.

''There are people in the process of boarding up windows and removing cracked windows,'' said Gordon Jones, a Sears spokesman.

The windows, 5 feet wide and 8 feet tall, began shattering and cracking at about 3:30 a.m. when gusts of up to 56 mph were recorded in the area, said Ernest Arms, another spokesman for Sears.

Jones and Arms said it appeared that one or more windows was broken by debris, perhaps pebbles from nearby roofs, and the others were broken as pieces came down.

However, Jones said, ''We don't really know - it happened in the dark.''

Jones said company officials did not have a damage estimate. All the cracked or broken windows were located between the 50th and 88th floors of the 1,454-foot building, said Arms.

Five windows were broken during high winds in April 1984, he said.