PARIS—France recorded its first case of the new variant of coronavirus, as the number of cases and deaths from COVID-19 mounted in the country, increasing concerns of a new wave of the virus hitting the euro zone’s second-biggest economy. The French health ministry said a Frenchman who recently arrived back in France from London had tested positive for the new variant of the coronavirus. The ministry said the case—the first in France—had been found in the city of Tours. The man in question arrived from London on Dec. 19. He was currently self-isolating and felt alright, the ministry added. British Health Secretary Matt Hancock had said on Dec. 14 that a spike in COVID cases in the United Kingdom might have been linked to the new variant of the virus in the country. Hancock said more than 1,000 cases of the new variant had been identified, mainly in southeastern England. …