UPDATE 1-Mountain Province to repay De Beers Canada C$59 mln

* To repay De Beers C$59 mln for settlement of sunk costs

* Mountain to have 49 pct interest in Gahcho Kue project

* De Beers to have 51 pct interest in Gahcho Kue

July 6 (Reuters) - Mountain Province Diamonds Inc (MPV.TO) said it would repay De Beers Canada Inc C$59 million ($50.6 million) to settle its share of historic sunk costs related to the Gahcho Kue diamond project in Canada's Northwest Territories.

The settlement is part of its amended joint venture agreement with De Beers regarding Gahcho Kue, in which Mountain Province will have a 49 percent interest and De Beers will have a 51 percent interest.

According to Mountain Province's website, in the 2002 agreement, it had a 44.1 percent interest in the project, while De Beers had a 51 percent interest and Camphor Ventures had a 4.9 percent interest.

Both companies have agreed to limit the sunk historic costs for the period ended Dec. 31, 2008 to C$120 million.

Mountain Province's shares closed at C$1.73 Friday on the Toronto Stock Exchange.

($1=1.166 Canadian Dollar) (Reporting by Isheeta Sanghi in Bangalore; Editing by Anne Pallivathuckal)