For years, watchdog groups have lamented that many government agencies continue to work with contractors that act unethically, commit fraud or perform poorly.

But as the U.S. government has tried to crack down on wasteful spending, the number of companies suspended and prohibited from contracting with federal agencies has grown significantly. And on Wednesday, the Government Accountability Office reported that even those agencies that previously were the least likely to end ties with questionable contractors are now taking actions against them more frequently.

Across the government, the number of suspension and debarment actions jumped from 1,836 in fiscal 2009 to 4,812 last year, an increase the GAO said was largely the result of an effort to beef up staffing and oversight of lucrative contracts and grants.

The report took particular note of six agencies that spend many billions of dollars a year on contracts but “had virtually no procurement-related suspensions and debarments” in 2009.

But after a campaign coordinated in large part by the Interagency Suspension and Debarment Committee to help the agencies root out questionable companies and work with inspector generals, the number of suspensions and debarments reported by the six agencies increased from 19 in 2010 to 271 last year, the GAO found.

The six agencies are the departments of Commerce, Health and Human Services, Justice, State and Treasury, as well as the Federal Emergency Management Agency.

The GAO also focused on the Department of Veterans Affairs, which more than doubled its suspensions and debarments from 34 in 2011 to 73 last year.

“The findings are good news for agencies,” said Scott Amey, general counsel for the Project on Government Oversight. “More importantly, agencies that once lagged in their contractor responsibility activities are now active, and as a result, risky contractors are not getting taxpayer dollars. Although the government has a very long way to go in this area, it is good to see the government correct its shortfalls rather than ignore them.”

Amey said there are still problems, however, including the timeliness of suspensions. He noted, for example, that BP was suspended by the Environmental Protection Agency more than two years after the 2010 Gulf of Mexico oil spill. (The suspension has since been lifted.)

Stan Soloway, the president and chief executive of the Professional Services Council, a trade group representing contractors, said the increase in action was not surprising, given the attention it has gotten in the White House and Congress.

“There clearly is a concerted effort to root out bad actors,” he said. “It’s been a focal point of the administration for a number of years.”

But he said agencies should guard against simply pumping up their numbers in an attempt to show they are cracking down. “It still has to be in cases where it’s warranted,” he said.

There have been some cases, he said, “that were real head-scratchers and really raised questions of fairness.”

The GAO report came at the request of Rep. Darrell Issa (R-Calif.), chairman of the House Committee on Oversight and Government Reform, who has pushed to streamline the process of making sure shoddy contractors stop receiving government contracts.

“The current process for keeping taxpayer dollars out of the hands of criminals, tax evaders, and the chronically incompetent is stove-piped, fractured, and inadequate,” he said in a statement last year.