** Whitehaven Coal shares WHC.AX rise 1.4% to A$5.87, highest level since March 21
** Jefferies raises PT to A$6.60/shr from A6/shr; maintains "buy" rating
** Brokerage notes focus on margins and operational production efficiency over near-term volume growth at co's Blackwater and Daunia projects in Queensland
** Says WHC on-track to meet A$100 mln ($65.18 mln) cost reduction target for FY25; further optimisation planned for FY26
** Both assets offer variety of expansion optionality, mostly targeting lower-quality coal growth at lower margins - Jefferies
** Stock down 5.7% YTD
($1 = 1.5342 Australian dollars)
(Reporting by Kumar Tanishk in Bengaluru)
((Tanishk.Kumar@thomsonreuters.com; X: @thatstanishk;))