The next Opel Corsa will be based on Peugeot's 208 (pictured) if the deal goes ahead, while the Astra will be 308-based and so on.

Paris – French carmaker Peugeot-Citroen (PSA) expects its planned acquisition of General Motors' Opel division to lead to combined sales of 5 million vehicles by 2022 and save as much as 2 billion euros (27.4bn) annually, as the talks advance towards a likely deal in early March, sources told Reuters.

PSA also plans to make swift progress on technical convergence with GM's European arm, bringing new Opel models such as the popular Corsa mini onto the Paris-based manufacturer's own vehicle architectures to slash duplication, two people with knowledge of the matter said on Wednesday.

Paris-based PSA and GM confirmed last week that they were in talks over a PSA-Opel tie-up to create Europe's second-largest carmaker by sales after Volkswagen.

PSA Group has pledged to respect existing Opel and Vauxhall job guarantees if it buys the European arm of General Motors, though some analysts say thousands of jobs are eventually likely to go for the deal to work.

GM has pledged not to impose forced redundancies on some of its German workforce until the of end 2018, union IG Metall said, while some existing agreements about building certain models at Opel stretch beyond 2020.

However, some analysts say PSA will eventually need to make big cuts to turn around loss-making Opel and sister brand Vauxhall in a European car industry that has struggled for years with overcapacity.