Shares of Cintas gained 5 percent, hitting an all-time intraday high of $117.65, while G&K shares soared 17 percent hitting an all-time intraday high of $97.52.
Cintas said it will buy all outstanding shares of G&K for $97.50 a share in cash. This represents a premium of 18.7 percent from the stock's Aug. 15 close. Including net debt, the deal values G&K around $2.2 billion.
Cintas CEO Scott Farmer said in a statement that his company has "a deep level of respect for G&K Services, its long and impressive heritage and its employees."
"Our companies share a dedication to customers, employees-partners and shareholders, which will build a great foundation for a successful combination," Farmer said.
Both stocks are on a tear this year. Cintas has climbed 24 percent in 2016, while G&K has surged more than 53 percent in the same period.