Hertz Global ( HTZ) will purchase a smaller, mid-market rival, Dollar Thrifty Automotive Group ( DTG).

FORBES: Connect

For more than a year, Avis Budget Group and Hertz Global Holdings have been working on deals for Dollar Thrifty.

FORBES: Dollar Thrifty Ends Sale Process, Says Hertz Deal Didn't Eliminate Antitrust Risk

But these city-specific fleets have yet to spread much beyond Paris, making global programs like Zipcar, Hertz on Demand and Car2go better bets for globetrotting travellers.

BBC: Pay-as-you-go rental cars