President Bush's nominee to head the Internal Revenue Service yesterday pledged, as have many IRS commissioners before him, to step up enforcement of the nation's tax laws and to continue modernizing the agency's computer systems.

Mark W. Everson also said he endorses the administration's proposal to turn over to private collection agencies efforts to recover about $13 billion in tax debts. More generally, he said he favors allowing private companies to compete for government work when that work is "commercial in nature and could be done by outsiders."

Everson noted that about 22,000 IRS jobs have been identified as fitting this description, though he did not say whether he would push to open them to private competition. He added that where competition is allowed, "more often than not the government wins" and the work remains within the agency.

Colleen M. Kelley, president of the National Treasury Employees Union, which represents rank-and-file IRS workers, said after the hearing that using private collectors is bad policy and that agency employees could do the work more cheaply because contractors would be paid up to 25 percent of the taxes they collect.

Everson's appearance before the Senate Finance Committee was in marked contrast with that of his predecessor, Charles O. Rossotti, five years ago. Rossotti's nomination came at the peak of a Republican-led attack on the IRS for allegedly using overzealous and abusive tactics in seeking to collect taxes. Rossotti appeared before a packed hearing room, with senators and spectators paying close attention to his plans to rein in the agency.

Now a key problem for the agency is its inability to pursue tax evaders. But only a handful of senators and spectators appeared yesterday, despite recent disclosures about Enron Corp.'s complex tax-avoidance deals, the spread of corporate tax shelters, historically low audit rates, and Rossotti's statements that the agency pursues only a quarter of Americans who fail to file a tax return.

A vote on the nomination has not been scheduled, but no opposition to Everson has surfaced, committee aides said.

Everson, 49, served in several federal agencies during the Reagan administration and was a business executive before returning to Washington in 2001 to join the Office of Management and Budget, most recently as deputy director.

He acknowledged that enforcement has "languished" as the IRS has wrestled with its computers and sought to improve customer service.

Although the IRS has about 100,000 employees and an annual budget that will top $10 billion if the administration's current request is approved, Rossotti said late last year that 60 percent of identified tax debts are not pursued, 75 percent of taxpayers who did not file a return are not pursued, 79 percent of those who used abusive devises such as offshore bank accounts to hide income are not pursued. And the agency's statistics show that the chances of being audited have fallen to around 1 in 200 for individuals.

Everson accused accountants and lawyers of contributing to the decline in tax compliance, and he promised to put pressure on them.

"There are clear indications that professional standards have eroded in some corners of the practitioner community. Attorneys and accountants should be pillars of our system of taxation, not the architects of its circumvention," he said.

"People ran yellow and red lights they shouldn't have," he said, adding that he sees problems in every area -- ordinary taxpayers, corporations, small business, even among tax-exempt organizations where there is "a nexus . . . with terrorism."

To improve the situation, Everson promised to make it clear throughout the agency that enforcement is a priority. He also said he plans to improve training and staffing, especially for corporate audits -- "you can't be outmanned in this area," he said.

Everson added that modernizing the agency's information systems is essential to improving service to honest taxpayers and to catching cheats. He said that new computer systems continue to be put in service late and to be over budget, but that he hopes his private-sector experience will help him improve the agency's performance in this area.

Mark W. Everson acknowledged at the Senate hearing yesterday that IRS enforcement has "languished."