** American Renal Associates' shares  ARA.N  surge 64.9% to
$11.41 premarket 
    ** Co to be bought by a unit of private equity firm Nautic
Partners LLC for nearly $400 million, according to Reuters
calculations  urn:newsml:reuters.com:*:nBw5bfzhda
    ** ARA shareholders to receive $11.50/share in cash, a 66%
premium to stock's last close 
    ** ARA says the deal values co at an enterprise valuation of
$853 mln     
    ** The agreement includes a 40-day "go-shop" period, which
allows ARA board to solicit alternative deal proposals 
    ** Stock has fallen 33.3% YTD 

 (Reporting by Manas Mishra in Bengaluru)
 ((Manas.Mishra@thomsonreuters.com;
www.twitter.com/Manasmishra24; within U.S. +1 646 223 8780,
outside U.S. +91 806749 2709;))