U.S. companies desperate to hold on to workers in this tight labor market are beefing up benefits to part-time workers, according to a survey of 98 benefits professionals by RewardsPlus. The Web-based benefits firm conducted the survey in an effort to reveal which issues are important to benefits professionals in the workplace today. The survey showed that more than one-third of the companies that employ at least 1,000 part-time employees are increasing efforts to retain these workers. Furthermore, one-quarter of those companies plant to extend to part-time workers the same voluntary benefits they offer to full-time workers. RewardsPlus says on average, part-time employees work no more than 32 hours a week, with most working between 20 and 29 hours a week. The U.S. government defines part-time employees as working between one and 34 hours a week.