Registered nurses at Lower Bucks Hospital in Bristol Township ratified a four-year labor contract that includes wage increases and a guaranteed contribution to a 401(k) retirement plan, the Pennsylvania Association of Staff Nurses & Allied Professionals said Tuesday.

The contract covering 160 members of the Nursing Association of Lower Bucks Hospital passed by a "substanital majority," the union said, but it declined to share the exact vote. The for-profit Prime Healthcare Services Inc. bought Lower Bucks out of bankruptcy in 2012.

Jerry Silberman, the lead negotiator for the nurses said the contract includes wage increases averaging 10 to 11 percent over the life of the contract and adds expererience-based raises for nurses when they reach 25, 30, and 35 years of service.