Cintas Corp. and UniFirst Corp. may show the U.S. labor market is extending its two-year rebound when they release quarterly results in the next five weeks.

Investors such as Lawrence Creatura at Federated Investors Inc. watch uniform-rental companies to gauge hiring trends for employees in manufacturing, automotive, hospitality and similar work. Even though these jobs account for only about 10 percent of employment, optimism in this industry can be "really symptomatic of the health of a wide swath of American businesses" they serve, said Creatura, who helps to oversee $370 billion as a fund manager in Rochester, New York.

Hiring among workers who wear uniforms grew 64,000 in October, the most since January's 88,000, according to an index created by Robert W. Baird & Co. Job gains at these businesses rose 2.2 percent from a year earlier to 31 million, outpacing the 1.5 percent increase for all nonfarm payrolls, Baird and Labor Department data show. November jobs numbers will be released Dec. 7.