The National Labor Relations Board has formally dropped its legal challenge against Boeing over a nonunion plant the aviation giant opened in South Carolina -- a move met with jeers by Republicans who long described the case as "frivolous" and anti-business.

The decision, announced Friday by the board's top attorney, comes after the Machinists union approved a 4-year contract extension with Boeing. As part of that deal, the union agreed to withdraw its charge that the company violated federal labor laws.

"This is the outcome we have always preferred," Lafe Solomon, the board's acting general counsel, said in a statement.

The NLRB counsel had originally challenged Boeing's decision to open the South Carolina plant, with the union claiming the company did so in retaliation for past strikes in Washington state. Under the recent deal, Boeing promised to build the new version of its 737 airplane in Washington state...

WASHINGTON – A contentious labor dispute between the government and Boeing Co. that spawned a national political fight likely will be settled after the company and the Machinists union announced Wednesday they'd reached a tentative deal on a new four-year collective bargaining agreement.

If the deal is finalized, it would appear to leave in place the work at a new $750 million Boeing plant in South Carolina, a right-to-work state where the company opened a new production line for its 787 airplane.

The National Labor Relations Board filed a lawsuit earlier this year alleging that Boeing violated labor laws by opening the South Carolina line.

Republican candidates for president should make Boeing’s fight with the National Labor Relations Board over a massive new plant near Charleston, S.C., a centerpiece of their campaigns next year, Sen. Lindsey Graham, South Carolina Republican, said Wednesday.

The battle between the aerospace giant and its labor unions and over the $1 billion manufacturing plant - the largest private investment in the state’s history - has developed into a major political brawl. The NLRB, now dominated by appointees of President Obama, has filed an action to block the nonunion plant from opening, infuriating South Carolina officials and sparking sharp criticism from congressional Republicans.

“From a Republican point of view, if you don’t see this as government overreach at its worst, if you don’t see this as payback politics at its worst, then you shouldn’t be leading our party,” Mr. Graham told editors and reporters at The Washington Times.

NORTH CHARLESTON, S.C. — The National Labor Relations Board’s bid to prevent Boeing from moving to South Carolina could harm the very state it is trying to protect by discouraging businesses from setting up shop there, Republican lawmakers warn.

A Washington state union has persuaded the NLRB to fight to bring work back from the plant that Boeing Co., the worlds largest aerospace manufacturer, has built here.

But a victory for the labor board would create an unfriendly business environment and stifle economic growth in Washington state and across the country, Republicans say, and the uncertainty eventually could force American companies to do business overseas...