WASHINGTON — Seeking to bolster the ailing U.S. Postal Service, federal regulators moved on Friday to allow bigger jumps to stamp prices beyond the rate of inflation, a move that could eventually add millions more dollars to companies' shipping rates from prescription drugs to magazine subscriptions.The Postal Regulatory Commission announced the decision as part of a much-anticipated, 10-year review of the Postal Service's stamp rates. It concluded that the post office's mounting red ink from declining mail volume and costs from its pension and health care obligations hamper the ability to provide reliable mail and package service in the digital age.The commission's plan would give the Postal Service freedom to raise the price of its first-class stamp, now at 49 cents, by an additional 2 percent above the rate of inflation to help avoid bankruptcy and make needed multi-billion dollar investments, such as upgraded information technology and new delivery trucks.The post office could also tack on another 1 percent to the stamp price if it met certain standards for "operational efficiency" and quality service.In all, that could translate to an increase of up to a few cents each year, depending on rates of inflation, compared with roughly 1 cent per year previously. The new pricing system would be in place for at least the next five years.Businesses immediately voiced objections, calling the regulatory plan "disappointing.""The more-than-doubling over 5 years at current inflation rates proposed by the commission would be harmful to postal customers and the Postal Service," said Art Sackler, manager of the Coalition for a 21st Century Postal Service, a broad trade group that includes mailers such as Amazon and the National Retail Federation.