HARRISBURG, Pa. – Jon Odom was an apprentice at an Arkansas electric cooperative, on his way to becoming a full-fledged lineman within several years, when he left to go to college.

Mr. Odom, 22, now attends Arkansas State University and is getting paid his regular wage of $13.24 an hour by the utility, which is also picking up his $3,000 tuition tab. The year of classes are designed to speed his lineman training, and, his employer told him, could make him a better candidate for management.

“Another guy might not get that opportunity because he doesn’t have that school background,” Mr. Odom said.

Classes began this fall for Mr. Odom and 11 other students, covering everything from pole climbing and driving a bucket truck to handling wires and transformers. Students attend for two semesters, and can use the credit toward an associate degree.

Young trainees like Mr. Odom are becoming increasingly valuable in Arkansas, Pennsylvania, and other states as utilities face a wave of retirements of linemen and power-plant workers in the next four to five years. To train replacements faster and cheaper than traditional in-house apprenticeship programs, many utilities are turning to colleges and universities for help.

The aging workforce can be traced to a sharp drop in employment by the electric power industry, from 550,000 in 1990 to 420,000 today, according to federal labor statistics. The decline slowed turnover and reduced opportunities for young trainees. As a result, many utilities slowed or stopped costly apprenticeship programs.

Now, some utilities are sending recruiters to high schools and taking other steps to prepare for the retirement of up to a third of their line workers by the end of the decade.

Union leaders and industry watchdogs say the work force changes are the product of a hiring freeze by utilities as they adapted to deregulation. Industry officials, however, say improving technology has diminished the need to replace retiring or departing workers.

Utilities say they can meet the demand with college trainees and rejuvenated apprentice programs, but union leaders say more must be done.