Employees of the U.S. Postal Service spent nearly $15,000 on season and group tickets to professional basketball, football and baseball games, “imprudent spending” that could damage the agency’s public image, auditors said.

The $14,778 tab for sports tickets in one unnamed city last year did not directly violate USPS purchasing procedures because they were bought for “recognition” awards for postal employees. But a report released last week by the agency’s inspector general said the expenses were “in direct conflict with the Postal Service’s objective of driving down costs in all operations and processes.”

Auditors, following up on two previous reports on Postal Service purchasing, found that oversight of credit card spending by managers improved in fiscal 2010 over the previous year, with a decrease in expenses to $239.4 million from $266.7 million.

But in addition to the sports tickets, the new audit identified more than $400,000 spent on business meals, including beer and wine, gift cards and employee gifts that were not justified, authorized or documented.

Auditors singled out the sports tickets, which consisted of six season tickets for a National Basketball Association team; six personal seat licenses and season tickets for a National Football League team; and six group tickets for 14 games for one major league baseball team. The teams were not named.

Auditors noted that the employees who were to receive the tickets as rewards for good service were not designated.

USPS officials agreed with the findings, the audit says. They have agreed to issue a memo by Sept. 30 reminding employees about imprudent spending and the policies and procedures governing purchases.

Previous audits in 2008 and 2009 found tens of thousands of dollars in undocumented credit card purchases.