The tentative contract included a raise of 19% over five years.

United Auto Workers and Mack Trucks have been negotiating for three months over wage increases, cost-of-living allowances, job security, pensions, overtime, and prescription drug coverage, but union workers turned down a tentative contract agreement and voted to go on strike. More than 4,000 United Auto Workers (UAW) members working at the Mack Trucks, which is Volvo Group-owned, went on strike at factories in Florida, Maryland, and Pennsylvania.

The tentative contract included a raise of 19% over five years, Causes.com reported.

“I’m inspired to see UAW members at Mack holding out for a better deal, and ready to stand up and walk off the job to win it,” Shawn Fain, UAW president, said.

Mack Trucks’, one of North America’s largest manufacturers of medium-duty and heavy-duty trucks, engines and transmissions, tentative contract also includes a “$3,500 ratification bonus, improved retirement benefits, additional vacation for some employees and a reduction in the time needed to get to top pay” and an immediate 10 percent pay increase upon ratification, Reuters reported. It also increased annual payment to 401(k) plans to $1,000 to help with retirement health care costs for hires starting in 2009 and a pension benefit increase.

Stephen Roy, president of Mack Trucks, said he was “surprised and disappointed” that workers went on strike.

“We are committed to the collective bargaining process, and remain confident that we will be able to arrive at an agreement that delivers competitive wages and benefits for our employees and their families, while safeguarding our future as a competitive company and stable long-term employer,” Roy said.