(Adds background, deal details and share move) 
    July 17 (Reuters) - Canada's Dominion Diamond Corp  DDC.TO  
 DDC.N , the world's third-largest diamond producer by market 
value, has agreed to a sweetened takeover offer of $1.2 billion 
from The Washington Companies. 
    Dominion said Washington Companies will acquire all of its 
outstanding common shares for $14.25 per share in cash, higher 
than the U.S.-based company's earlier offer of $13.50 per share. 
 urn:newsml:reuters.com:*:nBw5K0qMpa 
    Washington Companies, founded by industrialist and 
entrepreneur Dennis Washington, has mining, industrial and 
transportation businesses across North America. 
    Dominion launched the sales process in March following an 
unsolicited $1.1 billion approach from Dennis. 
    Dominion, which owns a majority stake in the Ekati mine and 
minority share of the nearby Diavik mine in Canada's Northwest 
Territories, rejected Washington's initial advance, saying it 
undervalued the company. 
    U.S.-listed shares of Dominion were up 4 percent in 
premarket trading on Monday. 
    The deal is expected to close in the fourth quarter of 2017, 
Dominion said. Dominion will be required to pay Washington $43.9 
million in case of a deal cancellation. 
    Reuters reported on Friday that Dominion was in advanced and 
friendly talks with Washington Companies.  urn:newsml:reuters.com:*:nL1N1K5117 
    TD Securities was Dominion's financial adviser on the deal 
and Stikeman Elliott LLP its legal adviser. 
    BDT & Co LLC provided financial advice to Washington. Blake, 
Cassels & Graydon LLP and Skadden, Arps, Slate, Meagher & Flom 
LLP were its legal counsel. 
 
 (Reporting by John Benny in Bengaluru; Editing by Maju Samuel) 
 ((John.Benny@thomsonreuters.com; +1 646-223-8780; Reuters 
Messaging: John.Benny.thomsonreuters.com@reuters.net)) 
 
Keywords: DOMINION DIAMOND M&A/WASHINGTONCOMPANIES (UPDATE 1