washington britain loom exit european union another huge setback negotiations massive u.s.-eu free trade deal already stall deeply entrench differences grow anti-trade sentiment side atlantic historic divorce launch thursday vote almost certainly delay substantial progress transatlantic trade investment partnership ttip talk remain 27 eu state sort new relationship britain trade experts say friday french german officials increasingly voice skepticism ttip chance success unite kingdom departure deal could sink hop deal president barack obama leave office january yet another reason ttip likely postpone say heather conley european program director center strategic international study think tank washington honest ttip go anywhere believe 2018 early say u.s. trade representative michael froman say statement friday evaluate uk decision impact ttip would continue engage european uk counterparts importance trade investment indisputable relationships european union unite kingdom froman say economic strategic rationale t-tip remain strong ttip negotiators still expect meet brussels mid-july schedule talk aim focus less controversial issue leave thorny disagreements u.s. eu political leaders resolve unclear britain launch formal separation proceed take least two years analysts say side reluctant put best offer table new u.s. president due take office january french german leadership elections near 2017. brexit also preoccupy eu officials come months launch negotiations london future term uk-eu trade sort post-brexit priorities say hosuk lee-makiyama director european centre international political economy brussels-based think tank britain departure could leave u.s. negotiators face european side dug-in issue say chad bown senior fellow peterson institute international economics think tank washington uk part coalition liberal trade economies eu u.s. lose one like-minded countries group brussels sit side negotiate table say bown former world bank economist however lee-makiyama also see little chance deal 2018 say britain departure could eliminate one source disagreement uk insist financial service chapter trade deal real proponent bank regulation ttip uk germany france probably will let go say still leave 20 outstanding issue nearly level difficulty ttip negotiations start three years ago unable settle major differences agriculture eu side show little willingness alter food safety rule prohibit american beef raise hormones genetically modify foods open closely guard geographical food name rule asiago feta cheese european negotiators complain unite state offer little open vast federal state local government procurement market european vendors buy american preferences place europe also want access key u.s. sectors maritime transport aviation american negotiators frustrate lack access 200 european sectors range healthcare education two side also far apart resolve dispute u.s. side favor traditional bind arbitration approach europeans want court-like system allow appeal progress make harmonize regulations things like car seat belt anchor clothe label pharmaceutical inspections uk 'leave vote deflate hop u.s.-eu trade deal