The United States and France have settled a two-month-old dispute that paves the way for lower air fares to France-not quite as low as the Americans wanted, but lower than the French wanted.

As a result of the negotiations, Braniff International will be able to offer lower fares to Paris from Boston and Dallas-Fort Worth than have been available thus far, and plans to extend the benefits to connecting cities such as Washington. Also, for the first time, the French government has agreed to approve standby fares to Paris.

In addition, Trans World Airlines will begin offering advance-purchase excursion fares to Paris with liberalized restrictions, and Trans International Airlines will be able to offer, if it chooses, new low-fare services to Paris.

The agreement also means that the Civil Aeronautics Board will probably ask President Carter to lift the suspension that had been imposed on a new "Vacances" low-fare plan that had been proposed by Air France.

The CAB had recommended that President Carter suspend the Vacances fare because the French government was balking at the low-fare proposals of U.S. airlines, a recommendation he adopted.

"We didn't get everything we wanted, but we did get a significant amount," Michael E. Levine, director of the CAB's Bureau of Pricing and Domestic Aviation, said yesterday. "It is possible that by precipitating a crisis, we might have gotten more, but the long-run benefits to our aviation policy and to consumers of preserving good aviation relations with France justified a compromise."

Besides not getting fares quite as low as desired, the U.S. did not win as much freedom as it wanted for U.S. airlines to charge what they wanted for passengers originating from France, and, according to Levine, the United States "gave up the principle-for the moment, that we don't negotiate fares."

With a 7 percent fuel surcharge the United States agreed to on all but normal economy fares, effective June 1, Braniff will begin offering a $353 roundtrip standby and budget fare to Paris from Boston (its original proposal including the fuel surcharge would have been $341); it will offer a $386 roundtrip fare for those who want reservations and can book their flights in advance; the fare is exactly half the roundtrip economy fare.

The Air France "Vacances" slated for approval is also $386 roundtrip, with the fuel surcharge, from New York; for the fare, Air France has dedicated a Boeing 747 with more seats than usual which will leave three days a week and return three days a week. There are no advance purchase restrictions and a stay between 14 and 60 days will be permitted.

TWA won, for passengers leaving from the U.S., the right to reduce the advance-purchase requirement on excursion fares to 21 days from 30 and to get a seven-day minimum stay requirement instead of 14.