Organized labor apparently has blocked the nomination of President Carter's choice to succeed Robert Strauss as special trade representative, according to administration sources.

Sources said yesterday that labor "shot down" the selection of Lloyd Hackler, president of the American Retail Federation and veteran political adviser, during a meeting last weekend. The unions oppose Hackler because of his opposition to labor law reform legislation in the last Congress.

Hackler, a former deputy White House press secretary in the Johnson administration and aide to Sen. Lloyd Bentsen (D-Tex.), is a political associate of Strauss.

AFL-CIO sources claim the White House tried to make a political end run around the federation by taking the Hackler nomination to individual unions for approval first. But the choice ran into heavy opposition at the individual union level too, particularly from the clothing and textile unions.

Sources close to the administration said the White House wants to wait until Strauss, who is now serving as the U.S. Mideast negotiator, returns to Washington later this month before making any further move on the Hackler nomination. The White House would still like to push the Hackler nomination, sources said.

"The White House wants to wait a while to see if Labor cools down (on Hackler)," a source said. "If they want it, they'll get the politics worked out."

After last weekends's rejection by labor, the White House is now reportedly considering Harry Macpherson, another former Johnson White House aide, for the Strauss job. Macpherson, currently in law practice in Washington, said this week that he had not been contacted about the job.

Other names being mentioned in connection with the trade post are: Sol Linowitz, former OAS ambassador and a U.S. negotiator on the Panama Canal treaty; John Moore, president of the Export-Import Bank, and Lee Kling, former treasurer of the Democratic National Committee and currently an aide to Strauss.