Buffeted by threats from alternate delivery services, the U.S. Postal Service, an independent agency of the government, has lost money for 10 years and is now looking at a different strategy: more freedom to raise stamp prices.

WASHINGTON — Regulators appear likely to accept the financially beleaguered Postal Service’s request for more freedom to raise the price of mailing letters. It would be the biggest change in the Postal Service’s pricing system in nearly a half-century, allowing stamp prices to rise beyond the rate of inflation.

After a 10-year review, the Postal Regulatory Commission could make its decision next month.

It might limit how high prices could go, but the cost of a first-class stamp, now 49 cents, could jump. It’s not known how much.

Financial analysts praise the plan, but it has raised the ire of the mail-order industry, which could pay millions more for sending items like prescription drugs and magazines and pass the costs onto consumers.

The Postal Service is trying to stay financially afloat as it seeks to invest billions of dollars in new delivery trucks to get packages more nimbly to American homes.

An independent agency of government, the Postal Service has lost money for 10 consecutive years.

While online shopping has led to years of double-digit growth in its package-delivery business, it hasn’t offset declines in first-class mail.

Overall mail volume, which makes up more than two-thirds of postal revenue, dropped 27 percent over the last decade as people rely more on email and online bill payments.

Congress’ failure to address the Postal Service’s underlying financial woes, such as onerous requirements to pre-fund retiree health benefits, has left the commission more likely to embrace the request for more pricing freedom. The Postal Service has ruled out closing post offices and ending Saturday delivery to reduce costs.

“We are calling for action from Congress, but we’ll do what we have to, based on the reality of what is,” Robert Taub, the Republican chairman of the regulatory commission, said in a telephone interview.

He declined to comment on the upcoming decision, but stressed a need to fix the balance sheet at the 242-year-old Postal Service, which generates $71 billion in annual revenue.

The decision comes as internet sales continue to flourish, led by Amazon, spurring consumer demand for ever-faster and cheaper delivery.

Forty percent of the e-commerce giant’s packages are delivered by the Postal Service, compared to 20 to 25 percent by United Parcel Service and 15 to 20 percent by FedEx, thanks to lower package delivery rates the Postal Service can offer because it already delivers to every U.S. household six days a week.