The health network that runs Danbury and Norwalk hospitals has completed a deal with a four-hospital group in New York to form a medical system that stretches from the Hudson River to the Long Island Sound. Federal and state agencies approved the $2.4 medical system, known as Nuvance Health, which will serve an estimated 1.5 million patients with 12,000 employees and 2,600 physicians, according to a release. Large-scale layoffs are not planned, although there are likely to be redundant positions at the department head level, said Dr. John Murphy, the CEO of Nuvance. \u201cThrough the new integrated health system, we will be able to attract top clinical talent in order to provide even more advanced, compassionate and collaborative care,\u201d Murphy said in a prepared statement on Tuesday. The top executive of the four-hospital group in New York agreed. \u201cBy coming together, we will bring our communities more health care options through new programs and services, especially to help prevent disease and effectively manage chronic conditions,\u201d said Robert Friedberg, president of Nuvance. The\u00a0merger, announced one year ago, places under single ownership Connecticut hospitals in Danbury, Norwalk, New Milford and Sharon, and New York hospitals in Carmel, Poughkeepsie and Rhinebeck. The merger required approval from the Federal Trade Commission and the health departments and the state attorney generals in Connecticut and New York.