** Federal Energy Regulatory Commission approves full service of TransCanada’s Mountaineer XPress (MXP) project
** This will help the Canadian pipeline operator increase the flow of gas on MXP and begin operating its Gulf XPress project
** The pipelines will take natural gas from the Appalachian basin to other markets
** The MXP project and related infrastructure represent an investment of $3.2 bln, TRP says
** On Thursday, TRP stock edged down 0.2 pct at C$58.85 (Reporting by John Benny in Bengaluru)
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