The continued decline in mail and parcel volume contributed to a 64% drop in controllable income for the U.S. Postal Service during the first quarter, underscoring why Postmaster General David Steiner is pushing to grow revenue through higher rates and a new program aimed at attracting retailers to handoff e-commerce shipments for last-mile delivery. More than 1,200 companies have shown interest so far in bidding for last-mile service, Steiner said in a presentation to the USPS Board of Governors on Thursday afternoon, adding that programs for first-mile package collection from retailers, as well as returns, could be established later this year. The fact that results went south during the strongest shipping period of the year, when seasonal surcharges and higher rates are applied, raises questions about the level of progress five years into a transformation plan designed to increase efficiency. Steiner, who took the helm last summer, acknowledged that more work remains to make the organization financially sustainable. Postal Service operating revenue dipped 1.2% to $22.2 billion, while expenses increased 4.6% to $23.5 billion, year over year for the three months ended Dec. 31, according to financial results released Thursday. Transportation costs, which have been heavily targeted by a multi-year transformation strategy, rose 2% to more than $2.4 billion. Controllable income, essentially adjusted operating income that excludes expenses such as workers compensation that are out of management’s control, plunged to $350 million from $968 million. Net loss for the quarter totaled $1.3 billion after the Postal Service posted a $144…