For the second time in under one month, workers at the agriculture equipment maker Deere & Company rejected a contract proposal negotiated by their union on Tuesday, extending a strike that began in mid-October.
Roughly 10,000 workers, primarily at plants in Iowa and Illinois, on Oct. 10 voted down an earlier agreement negotiated by the United Automobile Workers union.
“The strike against John Deere & Company will continue as we discuss next steps with the company,” the union said in a statement.
Marc A. Howze, a senior Deere official, said in a statement that the agreement would have included an investment of “an additional $3.5 billion in our employees, and by extension, our communities.”
“With the rejection of the agreement covering our Midwest facilities, we will execute the next phase of our Customer Service Continuation Plan,” the statement continued, alluding to its use of salaried employees to run facilities where workers are striking.
Many workers had complained that wage increases and retirement benefits included in the initial proposal were too weak given that the company — known for its distinctive green-and-yellow John Deere products — was on pace for a record of nearly $6 billion in annual profits.
According to a summary produced by the union, wage increases under the more recent proposal would have been 10 percent this year and 5 percent in the third and fifth years. During each of the even years of the six-year contract, employees would have received a lump-sum payment equivalent to 3 percent of their annual pay.
That was up from earlier proposed wage increases of 5 or 6 percent this year, depending on a worker’s labor grade, and 3 percent in 2023 and 2025.
The more recent proposal also included traditional pension benefits for future employees and a post-retirement health care fund seeded by $2,000 per year of service, neither of which were included in the initial agreement.
Chris Laursen, a worker at a John Deere plant in Ottumwa, Iowa, who was president of his local there until recently, said he voted in favor of the new agreement after voting to reject the previous one.
“We have the support of the community, we have the support of workers all around the country,” Mr. Laursen said. “If we turned down a 20 percent increase over a six-year period, substantial gains to our pension plan, I’m afraid we would lose that.”
But Mr. Laursen said he still had concerns about the vagueness of the company’s commitment to improving its worker incentive plan, and such concerns appeared to weigh on his co-workers, 55 percent of whom voted to reject the newer contract.
One wrinkle complicating the vote was suspicion among rank-and-file workers toward the union leadership related to a series of corruption scandals, which have led to more than 15 convictions, including two recent U.A.W. presidents.
The work stoppage at Deere was part of an uptick in strikes around the country last month that also included more than 1,000 workers at Kellogg and more than 2,000 hospital workers in upstate New York.
Overall, more than 25,000 workers walked off the job in October, versus an average of about 10,000 in each of the previous three months, according to data collected by researchers at Cornell University.