The latest in the leaky saga of PSA purchasing Opel from General Motors. After dealing with the hurdles of layoffs and labor unions, the PSA-Opel deal stumbles into it's latest problem: patents and pensions.

It was believed the deal was all but done, however, according to the Germans at Der Spiegel the latest stumbling block could be the use of GM held patents in Opel models. In particular Opel's rebadged Chevy Bolt, the Ampera-e.

GM has told PSA it will only licence the patents if the French brand agrees to keep the finished products out of North America, Russia and China.

The non-compete clauses would only apply to models containing GM held patents, meaning any models developed post-Detroit would be eligible for sale in North America provided they don't contain General Motors intellectual property. PSA Group CEO Carlos Tavares has hinted that under his stewardship Opel cars could be sold outside of Europe, but offered no specifics. Nearly 4,000 R&D jobs focusing on the US market at Opel's Rüsselsheim headquarters are likely at risk in light of the latest report from Germany.

Another equally contested, multibillion-dollar issue, is the plan for Opel and Vauxhall's underfunded pensions, PSA want's the business but not the legacy costs. According to Bloomberg, GM's European pension plan is underfunded by roughly $9 billion; PSA wants GM to keep a majority of that responsibility, while GM isn't really interested in shouldering the entire burden for a workforce it no longer employs.

It's thought PSA will pay roughly $2 billion for Opel and Vauxhall, a $1 billion purchase price and a further billion dollars toward liabilities. Even if GM is left holding $9 billion in pension obligations, it will be rid of a division that has been responsible for more than $9 billion in loses since the company emerged from the ashes of bankruptcy.