PARIS, Dec. 29 (AP)---Love has found a way to make a new, Franco-American match---a blow over the head with a champagne bottle. The Frenchman who was hit, Captain Allain Lemerdy, son of a General, is going to marry Clothilde Vail, sister of the American who flung the bottle. Cupid did his work while the two families, both prominent, were fighting out the bottle-throwing episode, which occurred in a Montparnasse café.

When Captain Lemerdy complained to the French court last March that he had been hit over the head with a champagne bottle by Lawrence Vail, American dramatist, Vail was sentenced to three months in jail and a 500 franc fine. He appealed and hired a lawyer to fight the case, seeking also the aid of the American Ambassador, Myron T. Herrick.

The Ambassador wrote a letter which was brought into court this afternoon, saying the Vails were of a fine American family, friends of France and descendants of one of the closest friends of General Lafayette. It developed that in recent months the two families held conferences out of court and that was how the Captain met Clothilde.

The Court withdrew the prison sentence and let Vail off with a 500-franc fine. His mother confirmed the engagement, but said no date had been set for the wedding.

Clothilde and Lawrence Vail are children of Eugene Lawrence Vail, American painter, officer of the Legion of Honor and long a resident of Paris.

Lawrence Vail married in Paris in March, 1922, Miss Marguerite Guggenheim, daughter of the late Benjamin Guggenheim, who lost his life in the sinking of the Titanic. They had met several years before in New York. Mr. Vail is 35 years of age.