The acting chief of the General Services Administration said Tuesday that he is canceling almost all bonuses for executives this year and freezing hiring after a spending scandal that prompted a major shake-up at the agency.

“We are examining all aspects of GSA’s enterprise including the agency’s long-term hiring needs and compensation process,” the acting administrator, Daniel M. Tangherlini, said in a statement to 12,600 employees posted on the GSA blog. The agency gave out $660,000 in executive bonuses in fiscal 2011, officials said.

The curbed bonuses and the hiring freeze are Tangherlini’s latest efforts to reform the agency that manages federal real estate and oversees most government purchasing. Since he stepped in as acting administrator in April after revelations by the GSA inspector general of lavish spending at a training conference in Las Vegas two years ago, Tangherlini has brought in a new management team and begun an aggressive review of the agency’s day-to-day operations.

Tangherlini said his review has uncovered “clear deficiencies in the area of performance awards,” with more than 15 bonus systems. “There are questions about the agency’s high award rate and questions about whether performance goals are set at a high enough level throughout the agency,” he said.

He has canceled numerous conferences and begun slashing travel budgets throughout the government by 30 percent. Among the biggest casualties is a major trade show for federal employees and contractors involved in government energy projects. Tangherlini pulled the plug on GovEnergy last week. Officials said the planned August conference failed to meet GSA’s new standards for conferences.

“After a rigorous review . . . GSA has found that the conference structure does not meet the standards that GSA has put in place for conferences and contracts,” the agency said in a statement.

Tangherlini referred his concerns about improprieties with planning for GovEnergy to the inspector general’s office, officials said.

Registrants and vendors will be reimbursed for money they put down. The total amount of those costs was not clear.

The decision to cancel was “not a statement on the importance of the conference,” the GSA statement said. GovEnergy was sponsored by industry contractors and numerous federal agencies, ­including the departments of Homeland Security, Defense, Energy and Veterans Affairs. It attracts thousands of vendors and attendees.

Tangherlini said he is cutting back bonuses for members of the Senior Executive Service by 85 percent for this fiscal year and suspending all hiring. He also ended an awards program that rewarded employees with iPods, digital cameras and other prizes.

The changes were criticized by the union representing GSA employees and the association of senior executives, which said they were overreactions.

“They’re going to fail to adequately recognize very good performers,” said William L. Bransford, general counsel for the Senior Executives Association. He predicted that fewer bonuses would mean “people are not going to be drawn to vacancies in the future.”
Of 75 career senior executives, 67 received bonuses in the past fiscal year, officials said. The average was $9,600, the same award given to Jeffrey Neely, the organizer of the much criticized Western Regions conference. Neely received his bonus even after GSA leaders had been briefed on the excessive spending.

William R. Dougan, president of the National Federation of Federal Employees, said the hiring freeze will “make it difficult to address critical vacancies, ultimately diminishing an agency’s capacity to accomplish its mission.”

Tangherlini, a former city administrator in the District who was assistant secretary for management at the Treasury Department, replaced Martha Johnson, who was forced to resign after the inspector general reported that GSA spent $823,000 to entertain 300 GSA employees for four days at an opulent hotel off the Las Vegas Strip.

Organizers brought in a mind reader, a clown and lavish food spreads, and top executives held after-hours parties in their luxury suites.