** Shares of UK-based oil and gas company i3 Energy I3E.L
jump 29.8% at 12.5p - a near 4-month high
** Co in advanced talks with Canada's Gran Tierra Energy
GTE.TO about a possible takeover offer
** GTE closed 2% lower on Monday, snapping a seven-session
rally
** Under the deal terms, each i3 energy shareholder will get
10.43 pence per share
** Gran Tierra has until Sept. 16 to table a firm offer or
walk away
** I3E stock up about 12% YTD
(Reporting by Yamini Kalia in Bengaluru)
((Yamini.Kalia@thomsonreuters.com;))