Smith Barney Harris Upham & Co analyst Barry Bosak has downgraded his investment opinion on IBM Corp’s shares to hold from buy and has cut his forecast for the fourth quarter by 70 cents to $2.50 a share, which implies $2.80 for the year – IBM did $4.30 a share in last year’s fourth quarter and $10.51 in the year; he has also slashed his 1992 forecast to $7.50 from the $10 he had been forecasting; the switches are in response to IBM’s sharp price cuts on PS/2s, the competitive environment and his belief that any economic recovery that occurs will turn out sluggish.