In a statement after the GM meeting, Mr Clark said: "I had constructive talks with GM this morning where I emphasised the importance and successful presence of Vauxhall in the United Kingdom and welcomed GM's recognition of the excellent and committed workforce at Ellesmere Port, Luton and across the UK".
Government ministers were in talks with the French firm last night, with business secretary Greg Clark being told that Vauxhall's "committed workforce" was highly valued by the PSA Group.
Clark said: "I had constructive meetings in Paris with both my French counterpart and executives of PSA Group, in which they explained the rationale behind this potential alliance".
PSA and GM have declined to say what cuts they would make to jobs, plants, production capacity or research and development under the deal being discussed. "We agreed to remain in close contact during the period ahead", Clark said.
The deal would include Vauxhall, which has plants at Ellesmere Port and Luton employing 4,500 staff.
New passenger auto registrations at PSA, including the Peugeot, Citroen and DS brands in the European Union and the European Free Trade Association rose 6.5 percent in January, compared with 5.3 percent for GM's Opel and Vauxhall brands, the Association of European Carmakers (ACEA) said on Thursday.
It has been widely reported that PSA is considering making a bid for Opel, the struggling European arm of General Motors (GM).
Spanish court acquits king's sister, Princess Cristina, of tax fraud
King Juan Carlos, the father of Felipe and Cristina, abdicated in 2014 as the investigation into the scandal played out. She was the first member of Spain's royal family to face criminal charges since the monarchy was restored in 1975.
"We've got no intentions of allowing a single job loss", Len McCluskey, general secretary of Britain's Unite union, said during a television interview.
More than 3,000 jobs at two iconic Vauxhall vehicle plants in the United Kingdom are "at risk", says The Times. "Restructuring is very likely to happen at the Vauxhall plants".
The government of Germany's Rhineland-Palatinate region, home to Opel's Kaiserslautern plant, also welcomed the potential creation of a "European champion" on Thursday and indicated it had received assurances from GM.
"A more obvious weak point for GM's European manufacturing operations is its United Kingdom plants". PSA was overtaken by rival Renault a year ago as France's biggest carmaker by volume.
After the GM talks, Clark said he "emphasised the importance and successful presence of Vauxhall in the United Kingdom and welcomed GM's recognition of the excellent and committed workforce" at Ellesmere Port and Luton. It later took a stake in Peugeot in 2012, but sold it the following year.
The tie-up would mean GM leaving Europe, and PSA becoming the second-largest European carmaker with a 16% market share.