Centene Corp. is acquiring Woodland Hills-based managed care provider Health Net in a deal valued at $6.8 billion. The deal, which is expected to close by early 2016, will add Health Net's Medicare platform to Centene's existing Medicaid programs and create a managed care firm with more than 10 million members nationwide and approximately $37 billion in revenue. Under the terms of the deal, Health Net shareholders (NYSE: HNT) will receive 0.622 shares of Centene common stock (NYSE: CNC) and $28.25…