Pharmaceutical giant Bayer said Friday that it will halt sales of its controversial Essure birth-control device in the United States at the end of the year.The move will bring to a close a protracted battle over an implant that thousands of women blame for serious health problems, including persistent pain and perforations of the uterus and fallopian tubes.The company said Essure’s removal from the market was “business decision” prompted by precipitous declines in sales in recent years.It said in a statement that it stands by the safety and effectiveness of the device, and added that women who currently have Essure in place can continue to “confidently” rely on it.The United States is the last country where Essure is being sold.