By Tim Hepher and Karen Lema PARIS/MANILA, July 10 (Reuters) – Philippine Airlines (PAL) is poised to order 15 Boeing 787-10 aircraft and nine Airbus A350-1000 jets, marking its first Boeing purchase in almost 20 years, industry sources said on Friday. The orders are expected to be announced at the Farnborough Airshow this month. The decision to include the Boeing 787 will automatically trigger a separate engine contest between Britain’s Rolls-Royce and U.S. giant GE Aerospace.