The U.S. Postal Service faces a leadership succession problem due to pending retirements among executives, but many of those in line to take their places aren’t far from retirement eligibility themselves, a report issued Monday said.

The postal inspector general’s office said that as of 2012, 35 percent of postal executives already were retirement-eligible and that the number will grow to 49 percent in 2015.

However, it added, “about 30 percent of potential successors are eligible to retire now, and 73 percent will be eligible in the next seven years.”

Postal employees fall under the same two major retirement systems as other federal employees despite the self-funding nature of the Postal Service. Those programs allow for retirement when an individual reaches one of several combinations of age and years of service.

“With many impending executive retirements and considering the numerous years required to develop effective leaders at the executive level, the Postal Service finds itself at a critical juncture in its history. Unless the agency invests in identifying and developing potential successors to build a stronger leadership pipeline, it risks significant operational disruptions,” the report said.

Warnings about the potential impact of a “retirement wave” in the overall federal workforce have been sounded for many years. The Government Accountability Office recently said that a surge of retirements “could produce mission-critical skills gaps if left unaddressed.”

The average federal worker age is 47 — compared with 42 for the American workforce as a whole, according to the White House’s most recent budget proposal — and 43 percent are age 50 or older.

Retirements of federal employees have increased each year since 2010 as more Baby Boom-era employees reach eligibility combinations. In addition, the Postal Service has offered several rounds of early retirements as a cost-saving measure.

The report noted that the Postal Service uses a “Corporate Succession Planning” program to identify and develop top performing employees for new or expanded executive roles. Participants in that program fill all but a few percent of executive positions that become vacant.

“However, we found that management did not always timely approve developmental activities because approving these activities was not a priority. These delays hindered potential successors’ ability to develop skills they needed for leadership positions,” the report said.

Further, Postal Service officials told the auditors that retirement eligibility does not preclude someone from being in the program.

In its response, Postal Service management agreed to ensure that developmental opportunities are approved on schedule.