By Tim Hepher PARIS (Reuters) -Airlines group IAG is in advanced talks with planemakers on a medium-haul fleet shake-up that may see the British Airways parent opt for Boeing and Airbus jets to update a European fleet of Airbus narrowbodies, industry sources said. IAG stunned the industry nearly three years ago when it unveiled a tentative order worth $24 billion at list prices for 200 Boeing 737 MAX at the Paris Airshow in 2019, at a time when the jet was grounded worldwide in the wake of two fatal crashes. The global outbreak of COVID-19 early the following year caused that deal – intended a…