[Bloomberg] German Chancellor Angela Merkel will quit as head of her Christian Democratic party after almost two decades, a person familiar with the matter said, a dramatic sign of her waning authority that will raise questions about her staying power as chancellor.The unexpected reversal by Merkel, 64, signals the beginning of the end of an era during which her command of Germany put its stamp on Europe and beyond for more than a decade. Even so, Merkel's term as chancellor runs until 2021 and Merkel has said she intends to serve it out. She is scheduled to speak to the media at 1 p.m. local time in Berlin.