WASHINGTON — The financially troubled Postal Service on Friday reported a net loss of $1.9 billion in the second quarter, the same amount it lost over the same period in 2013, postal officials said.

But the service did report operating revenue of $16.7 billion, a $379 million increase over the same period last year. It was the third straight quarter it had posted an increase in revenue.

Postal officials admitted, however, that the increase in revenue as well as efforts to trim costs — like cutting back the hours at many post offices, reducing staff through attrition and consolidating about half of the service’s processing plants — were not enough to offset its debt.

According to a Government Accountability Office report, the Postal Service owes $99.8 billion in benefit payments to its current and retired workers, including $16.7 billion of congressionally mandated payments into a future retiree health care fund. A 2006 law requires the service to fund its future retirees’ health benefits, amounting to a $5 billion payment each year for 10 years.