WASHINGTON — The U.S. Postal Service reported a $1.9 billion loss for the first three months of this year and pleaded again Friday for reforms to its troubled financial system.

The agency said the loss for the quarter that ended March 31 matched the $1.9 billion in red ink in the same period last year and marked the 20th time of the last 22 quarters that it posted a loss.

It came despite continued cost-cutting efforts, a 2.3 percent rise in operating revenue, increased employee productivity and other improvements.

“We’re happy with the financial progress,” Postmaster Patrick Donahoe told reporters on a conference call. “Bottom line: Unfortunately, we’re still in the red” because of congressionally mandated retiree payments.

Postal officials have said repeatedly that they need comprehensive legislation that includes more control over personnel and benefit costs and more flexibility in pricing and products.

The shipping and package business continued to rise and operating revenues were up $379 million over the same period last year – the third straight quarter of increase. But there were annual inflationary cost increases and there was a continued drop in first-class mail.

Details in the report for the second quarter of the budget year, compared to the same period last year, included:

• Operating revenue was $16.7 billion, an increase of $379 million, or 2.3 percent.

• Operating expenses before non-cash workers’ compensation expenses were cut to $17.9 billion from $18.1 billion.

• Total mail volume fell to 38.1 billion pieces from 38.8 billion.

• Volume in shipping and packages rose 7.3 percent.

• First-class mail declined 4.1 percent.