** Lufthansa says the first flight of its revamped Eurowings brandwill take off on Sunday
** The Airbus A320, the first A320 in the Eurowings fleet and sporting thenew blue and purple livery, will fly from Hamburg to Prague, departing at 0955GMT
** Lufthansa is battling to regain market share lost to Ryanair,easyJet and Vueling and wants to use Eurowings to attractprice-sensitive leisure customers
** It also plans to use the brand for low-cost long-haul flights later thisyear
** Costs at Eurowings are 40 pct below that of the group's main Lufthansabrand (RM: victoria.bryan.thomsonreuters.com@reuters.net)