The Daughters of Charity hospital chain has filed a lawsuit against SEIU-United Health Workers West, alleging the union used "extortionist threats" as part of its effort to block the chain's sale of its six hospitals to Prime Healthcare.
Last week Attorney General Kamala Harris gave conditional approval to the controversial sale.
Daughters of Charity claims in its suit that the union improperly interfered with the proposed sale - which includes St. Vincent and St. Francis Medical Centers in Los Angeles. Another bidder for the chain, equity firm Blue Wolf Capital Partners, is also named in the lawsuit.
Daughters of Charity alleges the union and Blue Wolf used what it called threats and tactics to hold the deal "hostage" - creating delays that cost it tens of millions of dollars. The lawsuit was filed in Santa Clara County.
The defendants' actions "have caused real and substantial harm to [Daughters of Charity] and it intends to vigorously prosecute its claims," the non-profit hospital chain said in a statement.
The union said all of its actions surrounding the proposed sale were part of its work advocating on behalf of workers.
"This is nothing more than a legal hissy fit, and no lawsuit is going to stop healthcare workers from speaking up to protect their patients, workers and communities," said Dave Regan, president of SEIU-UHW.
The lawsuit seeks unspecified financial damages.
The sale of the hospitals to Prime, a for-profit corporation, is still pending. Prime has not yet decided whether to move forward under the conditions set by the attorney general.