HARRISBURG — UPMC says it’s agreeing to allow some Highmark insurance enrollees under certain conditions to continue using its doctors and facilities at in-network rates.

Gov. Tom Corbett and Attorney General Kathleen Kane and officials from the two companies announced the deal this morning, although some details remain under negotiation. A contract between the two Western Pennsylvania health care giants ends Jan. 1 after a bitter fight between the two.

Most Highmark subscribers stand to lose in-network access to UPMC doctors and hospitals after Dec. 31.

Under the agreement, doctors can keep patients who are in the middle of a course of treatment in network at UPMC for as long as necessary.

Other Highmark enrollees will be able to keep their doctors for a year if they can’t find an alternative.