Updated

In a new sign of dissatisfaction within organized labor, two national trade unions broke away Tuesday from an alliance affiliated with the AFL-CIO after complaints about declining membership and misplaced priorities.

The Laborers International Union and the International Union of Operating Engineers, representing more than 1 million members, are breaking away from the umbrella group known as the Building and Construction Trades Department of the AFL-CIO as of March 1. The umbrella group still has 11 unions representing about 2 million workers.

The Laborers and Operating Engineers will join with four other unions in the construction business -- the Teamsters, Carpenters, Iron Workers and Bricklayers unions -- to form the National Construction Alliance, a confederation aimed at expanding union membership in the construction field. The new alliance will focus heavily on building union strength in almost 30 states where the construction business has low union membership.

"While the construction economy has grown, living and work standards for construction workers have fallen," said Terence O'Sullivan, Laborers' president. Union representation among construction workers has fallen from 40 percent in 1973 to 13 percent now, he said.

O'Sullivan and Operating Engineers President Vincent Giblin said they were frustrated with the umbrella group's lack of action to reverse declines in membership, outdated rules and priorities more focused on Washington politics than membership recruitment, workplace safety and job security.

Sean McGarvey, secretary-treasurer of the umbrella group losing two members, said: "It's unfortunate they chose this time, with a great opportunity for the union construction trades to take advantage of this huge construction boom over the next five to 10 years and regain hundreds of thousands of members. We work best when we work together."

The two trade unions remain in the AFL-CIO, which has seen a half-dozen of its unions break away from the federation over disputes about political priorities and organizing strategies.

O'Sullivan said the Laborers' decision about whether to leave the AFL-CIO is "not a matter of if but when." Giblin said "the jury is out" on the Operating Engineers' future in the AFL-CIO.

When the AFL-CIO formed 50 years ago, union membership was at its zenith, with one of every three private-sector workers belonging to a labor group. Now, about 12 percent of all workers are unionized, but fewer than 8 percent of private-sector workers belong to unions.