Workhorse also put out a press release late Thursday that outlined details of the intellectual property licensing agreement it has with Lordstown Motors.
Neither company indicated Thursday the number of jobs and when hiring or production would begin. But GM has said the business would create about 450 jobs.
Workhorse CEO Duane Hughes said it appreciated "GM's acceptance of our combined proposal and believe it represents the best opportunity to keep production in Lordstown. We look forward to working together in the future as we finalize this transaction and explore additional production possibilities at the plant."
Lordstown Motor's Burns said: "We, along with Workhorse, remain dedicated to keeping vehicle production in Lordstown. Now, with LMC's acquiring of the Lordstown, Ohio, factory, it is time to begin executing on our plan."
Shares of Workhorse Group closed up 27.24% at $3.13 Thursday.
Workhorse, based in Cincinnati, is one of five finalists to win a lucrative U.S. Postal Service contract worth $6.3 billion to build 180,000 next-generation mail delivery trucks. Mahindra Automotive North America Inc., an India-based automaker, is also a finalist. A decision is expected by the end of the year.
GM is still looking to build a battery cell plant in the Lordstown area that will create about 1,000 jobs, it said.
"Nothing's ever going to replace the 5,000 jobs in the GM plant and all the spinoff jobs," said Tim O'Hara, UAW Local 1112 president. "For the Mahoning Valley, any job is a good job, but we don't know what the jobs will pay and how many will be offered. If these turn out to be union jobs, it'll be good for the valley from that aspect."
A person familiar with the plans said the jobs are likely to start at $17 an hour.
End of GM at Lordstown