On Tuesday the state of Illinois approved the sale of one of Oak Park’s oldest and largest employers to a Tennessee corporation.

Nashville-based Vanguard Health Systems now has the go-ahead to purchase West Suburban Medical Center, the hospital at Austin Boulevard and Ontario Street in Oak Park. Vanguard, a for-profit company, plans to buy West Sub and its sister institution, Westlake Hospital in Melrose Park, for about $41.5 million from Chicago-based Resurrection Health Care.

At a meeting Tuesday morning in Springfield, the Illinois Health Facilities and Services Review Board voted 6-0 to approve the sale. The two parties have said they want to close the transaction by July 1, before the end of Resurrection’s fiscal year.

Resurrection was forced to seek buyers for the two hospitals because they were hemorrhaging money to the tune of $166 million over the past five years. Vanguard- owner of 15 hospitals in four states, including MacNeal in Berwyn-has committed to keeping the two hospitals open for at least three years after the closing date. The company has also pledged to invest $15 million in West Sub and Westlake.

“We look forward to finalizing the transactions and ensuring that these two hospitals will continue to serve the Oak Park and Melrose Park communities,” Vanguard and Resurrection said in a joint statement released Tuesday afternoon.

West Sub also serves patients from Austin. In their joint statement, the companies said they will both continue to work together to finalize the transaction.

“We look forward to working closely with hospital administration, medical personnel, other staff and supportive members of the community to ensure all employees are informed and involved in the smooth transition of both hospitals.”