The Abu Dhabi National Oil Company (ADNOC) has reached an agreement to buy German chemicals maker Covestro in what is set to be the biggest acquisition in the history of the United Arab Emirates and the largest Middle Eastern purchase of a European company. The $16 billion-plus deal comes at a sensitive time for Germany. Facing its worst economic crisis in a decade, the sale of Covestro represents the loss of another jewel in the industrial base of Europe’s largest economy after a spate of