Both companies last month confirmed that they were discussing a sale. Spokesmen for GM and PSA declined to comment.
The two brands that are now owned by General Motors shared numerous parts and technologies while the bowtie was sold in Europe, which led to the necessity of the non-compete restriction that may be applied to other markets where Chevy and Opel are present.
GM's European operations have lost money for 16 consecutive years and were nearly sold in 2009.
The "non-compete" clause was finally resolved when PSA made a decision to put in more into the pension, taking it up to $2 billion from $1 billion which was initially offered to GM.
Further details of the deal are not available at the moment, so we will have to wait for more insiders to provide classified information under cover of anonymity, or get the official version from the two firms. Detroit-based GM, which came close to selling Opel to Magna (MG.TO) in 2009, has faced investor pressure to offload its struggling European arm and focus on raising profitability rather than chase the global sales crown now held by VW.
As of March 2, GM and PSA had agreed upon narrowing down the differences on about $10 billion in Opel pension accountabilities and other issues.
"The UK market is the largest market in the European Union for Vauxhall/Opel so GM does have a moral obligation not to turn its back on the communities and workers who have helped make this company what it is today", Unite general secretary Len McCluskey said. PSA averted bankruptcy by selling 14 percent stakes to France and Dongfeng in 2014, to match a diluted Peugeot family holding.
Nevertheless, in a statement last week, PSA boss Carlos Tavares said he believes the tie up will offer "opportunity to create a European auto champion" with annual sales of over 5 million units. The French automobile manufacturer also expects to save at least $2.1 billion from this deal.
Tavares told his board that PSA would redevelop the core Opel lineup with its own technologies to achieve rapid savings, according to people with knowledge of the matter.