** U.S.-listed shares of Canadian energy firm Enerplus
ERF.TO ERF.N jump ~9% to $17.80 in extended trade
** Co to be acquired by U.S. oil and gas firm Chord Energy
CHRD.O in a cash and stock transaction
** Combined company to have an enterprise value of $11 bln
** ERF shareholders to receive 0.10125 shares of CHRD common
stock and $1.84 in cash for each share of ERF held at closing
** CHRD to issue 20.7 mln shares of its common stock
** CHRD shares up 2% at $171.50
(Reporting by Vallari Srivastava)
((Srivastava.Vallari@thomsonreuters.com;))