Nov 13 (Reuters) - Union leaders representing 50,000 nurses and other U.S. medical staff reached a tentative agreement with Kaiser Permanente on Saturday, averting a strike that could have disrupted patient care at hospitals. Thousands of employees at Kaiser Permanente in Oregon, California, Colorado and other states had threatened to walkout on Monday over the medical network"s plan to create a two-tiered wage system with lower pay for new hires. read moreKaiser and Alliance of Health Care Unions, which represents 22 local unions, agreed on a four-year contract that includes wage increases each year through 2025, the union said in a statement. https://prn.to/3CeFe63 The deal also includes health and retirement benefits and the introduction of a bonus plan. The statement did not include any financial details. "This agreement will mean patients will continue to receive the best care, and Alliance members will have the best jobs," Hal Ruddick, executive director of the Alliance union, said in the statement. "This contract protects our patients, provides safe staffing, and guarantees fair wages and benefits for every Alliance member," he added.Earlier, the union said the two-tiered wage system would deepen what the nurses describe as a staffing crisis in the midst of a COVID-19 pandemic. Kaiser ranks as one of the nation"s largest not-for-profit healthcare networks and managed-care organizations, with operating revenues of nearly $24 billion last quarter. "This landmark agreement positions Kaiser Permanente for a successful future focused on providing high-quality health care that is affordable and accessible for our more than 12 million members and the communities we serve," said Christian Meisner, senior vice president and chief human resources officer at Kaiser Permanente. Voting on the tentative agreement will occur over the next several weeks and once it is ratified, the agreement will be retroactive to Oct. 1, 2021.