Bayer has bid approximately $20 billion to acquire Schering AG. Schering, based in Berlin, is recommending the offer to its shareholders, according to a company statement. Schering also recently received an offer of $17.9 billion by Merck KGaA, which that company does not plan to increase. Currently, Bayer’s largest business is producing polyurethane, polycarbonates and other manufacturing materials, which accounted for about $13 billion in sales last year. Schering is a leader in or...