The Regional Telephone Directory has had a 69 percent increase in gross revenue so far this year compared to the same period a year ago, according to Ron Andrews, area sales manager.

He said the increased sales are attributed to lower advertising and listing rates and larger area coverage. The response has been so good that he increased his sales force from 18 to 37.The directory was introduced into Salt Lake City in early 1988 with a single telephone book combining the white and yellow pages and community features such as maps, street guides and talking or electronic information. Andrews said residential response has been higher than with any other first-year RTD directory.

Last May, the company conducted a survey and 97 percent of those polled said they received last year's directory and 69 percent reported regular use.

He attributes the residential usage of the telephone book to increased community information, more color and single-book convenience.