Signed, sealed and (almost) delivered.

The United States Postal Service — under fire from environmental groups — is no longer moving ahead with a plan to almost entirely replace its aging delivery fleet with gas-fueled trucks.

According to a posting on the USPS website quietly uploaded today, the agency will raise the target percentage of new electric vehicles in the fleet from just 10 percent to 50 percent. And instead of rush purchasing 165,000 new “Next Generation Delivery Vehicles” — 90 percent of them gas-powered — the Postal Service will reduce its order to 50,000.

Taken together, with new vehicles already purchased and those to be made, 40 percent of the 84,500 new vehicles will be electric.