The Minnesota Nurses Association said this morning that it intends to strike at 7 a.m. on July 6 if a contract settlement isn't reached with 14 Twin Cities-area hospitals.

The surprise notification came after negotiators for the two sides sat down with a federal mediator for the first contract talks in almost three weeks. The nurses voted overwhelmingly on Monday to authorize a strike, but union officials said they would postpone calling a strike as long as there were "productive" negotiations.

The 12,000 nurses staged a one-day walkout on June 10, which forced the hospitals to hire hundreds of temporary replacements, send patients to other facilities and postpone hundreds of elective procedures, but which appeared to cause only modest disruptions to patient care. But the open-ended walkout that nurses now contemplate could cause wider disruptions to Twin Cities medical care and inflict tens of millions of dollars in costs to both sides. It would be by far the biggest nursing strike in American history.

Neither side would say what transpired during Thursday's talks, which broke off at 9 p.m. Talks are expected to resume Tuesday.

Union spokesman John Nemo declined to elaborate on Thursday's talks, but a written statement posted on the union website expressed frustration.

"Our nurses spent more than 13 hours today doing our best to stay hopeful about negotiations," it reads. "Unfortunately, zero progress was made. Despite today's setback, our nurses offered to return to the bargaining table again on Friday, Saturday, Sunday and every other day until a contract agreement can be reached. Instead, the Twin Cities Hospitals responded that the earliest they could meet would be sometime next week. It has become beyond obvious to our nurses that the Twin Cities Hospitals, despite what they continue to say publicly, have no interest in meaningful or good faith negotiations."

A hospital spokeswoman expressed dismay over the development.

"This demonstrates that the union continues to pursue an aggressive strategy of pushing toward a strike," said spokeswoman Maureen Schriner. "The hospitals feel we owe it to our nurses and the community to stay at the bargaining table and not to have a strike."

mlsmith@startribune.com • 612-673-4788 dave.hage@startribune.com • 612-673-7108