China National Chemical Corp (ChemChina) is to buy Pirelli (PECI.MI), the world’s fifth-largest tire maker, in a 7.1 billion euro ($7.7 billion) deal that will place one of the symbols of Italy’s manufacturing industry in Chinese hands. The deal agreed with Pirelli shareholders on Sunday is the latest in a string of takeovers in Italy by cash-rich Chinese buyers, who can take advantage of a weak euro just as signs emerge that Europe is coming out of economic stagnation.