Average salary increases in 1989 will differ little from 1988 increases but employees will augment their salaries with new bonus and incentive arrangements, a survey released this week showed.

The Hay Group surveyed 952 companies attending the 1988 Hay Compensation Conferences in 15 cities nationwide and found average salary increases for executives and managers will be 5.6 percent in 1989, down from 5.8 percent in 1988.Increases for technical-professional employees will be 5.4 percent, with 5.2 percent increases scheduled for clerical-administrative employees and 4.7 percent increases for hourly workers.

"Although average increases do vary by specific company, industry or geographic region, over the past three years we have seen companies keep their average raises at about the same modest levels," said John Linton, vice president and regional director for Executive Compensation at Hay Group.

"The real story in the world of compensation focuses on incentive programs that help keep fixed people costs down, but reward strong performers for individual and group performance."