Agreement includes job protection until 2018
The deal is a sign of smoother relations between management and the Opel workforce, who have in the past clashed over how to return the money-losing European unit to profitability by 2015.
"For the company and its employees this is an important step toward securing our future," Ulrich Schumacher, Opel's head of personnel who joined in May last year, said in a statement.
Around 7,150 employees work at the three factories.
As part of the deal, which was signed on Thursday, Opel's management pledged to give the Ruesselsheim factory an additional model to build, to continue making the Corsa and Adam models in Eisenach, and to continue building components in Kaiserslautern.
The factory in Bochum is set to stop producing cars at the end of 2014.
Earlier this week, General Motors Co's new chief executive, Mary Barra, urged Opel's workers to accelerate the European brand's turnaround and said the global auto maker was committed to supporting its loss-making European unit.
Fixing Europe, where Opel CEOs have come and gone in rapid succession and where GM has lost some $18 billion over the last 12 years, is at the top of Barra's to-do list.
General Motors has described 2014 as a "transition year" in Europe, where Opel will introduce a redesigned Corsa subcompact late in the year. A redesigned Astra compact is expected to follow in early 2015, along with new families of gasoline and diesel engines, helping to drive GM's European operations back to break-even.
Frankfurter Allgemeine Zeitung was first to report that Opel and its management had signed a deal.
