The number of working domestic oil and gas rigs rose by 17 to 897 this week, Baker Hughes Inc. reported Monday.

The rig count, the widely watched industry index of drilling activity, dipped the week before by 28 to total 880. A year ago, the count totaled 767, Baker Hughes said.Houston-based Hughes Tool Co., an oil toolmaker company that merged with Baker International Corp. of Orange, Calif., has kept track of the number of working rigs since 1940.

The rig count reached a peak of 4,500 in December 1981, the height of the oil boom. When oil prices plunged to less than $10 per 42-gallon barrel in the summer of 1986, the rig count declined to 663 - the lowest since Hughes began compiling figures.

Among major oil producing states, Louisiana gained nine rigs this week, while Wyoming added four, Michigan, three, and Oklahoma two.