The National Labor Relations Board on Tuesday released a decision that would make it easier to unionize nursing home workers.

It is the latest in a flurry of moves favorable to unions that the board completed before the term of its chairwoman, Wilma B. Liebman, expired on Sunday. The board released two other pro-union decisions on Tuesday, both reversing decisions issued under President George W. Bush.

In the nursing home decision, the board ruled that the union, the United Steelworkers, could organize just the 53 certified nursing assistants at a nursing home in Mobile, Ala., as part of one bargaining unit, without including the home’s 33 other nonprofessional workers, including janitors, cooks and file clerks.

Groups representing businesses and nursing home operators attacked the decision, fearing it would make the homes more vulnerable to unionization drives.

“This ruling makes it easier for unions to gerrymander who is in a bargaining unit to help them be successful in organizing,” said Michael J. Eastman, executive director of labor law policy at the United States Chamber of Commerce.