President Barack Obama has abandoned plans to impose tighter air quality rules in the United States, saying they would have imposed burdensome regulations on businesses when the country's economy is already on shaky footing.

Mr. Obama ordered government environmental regulators on Friday to stop implementation of a plan that soon would have required U.S. industries, states and communities to reduce emissions of smog-causing chemicals or face federal penalties. He said imposition of the rules now is not necessary because the ozone standard is already set for review in 2013.

Mr. Obama's decision is a significant victory for U.S. industrial and corporate interests. Business groups lobbied intensively against the proposed rules, saying they would cost them billions of dollars and force the layoff of thousands of workers.

Environmental groups criticized the president's stance, saying that he had sided with corporate interests at the expense of the health of Americans.

The president said the government during his tenure in the White House has already imposed a variety of stringent new clean air regulations. But rather than impose new rules, he said that as the country's economy recovers, it is necessary to “underscore the importance of reducing regulatory burdens and regulatory uncertainty.”

He said his administration would “vigorously oppose” efforts to weaken the country's main clean air law.