Exxon Mobil ( XOM.N ) plans to sell up to $25 billion of oil and gas fields in Europe, Asia and Africa in its biggest asset sales for decades, seeking to free up cash to focus on a handful of mega-projects, according to three banking sources. The sell-off would be a marked acceleration of the U.S. oil major’s previous divestment plans. It would represent an ambitious attempt by Chief Executive Darren Woods to catch up with competitors who carried out sweeping portfolio reviews and sold swathes of assets following the 2014 market crash. Exxon’s shares have underperformed its major rivals’ in recent years. The disposals would help the company increase spending on new developments and appease […]