The financially strapped, Massachusetts-based Caritas Christi Health Care hospital system is negotiating to buy the Landmark Medical Center, a 214-bed community hospital in Woonsocket, RI, that has been in court-appointed receivership for a year. Massachusetts and Rhode Island regulators say they will take a hard look at the potential merger. Caritas Christi's board has authorized its management to move forward with negotiations, according to three healthcare industry professionals. Officials at Caritas Christi and Landmark declined to confirm that a deal is close.