An expected investigation of Deloitte Touche Tohmatsu's audits of Dutch grocery giant Royal Ahold AV would be a major test of a U.S. law passed after last year's financial scandals and may influence the oversight of global accounting firms.

The new Public Company Accounting Oversight Board said yesterday that it will consider a plan next week to require all auditors -- even foreign ones -- to register with the board if the firms handle work for clients that sell securities in the United States. Foreign auditors have been lobbying to be exempt from the board's oversight, but the accounting problems at Ahold make that less likely, accounting experts said.

Meanwhile, Securities and Exchange Commission lawyers are preparing to use power that Congress gave it last year in the Sarbanes-Oxley Act, which allows them to subpoena audit papers from the overseas offices of big accounting firms. In the past, foreign branches of global accounting firms often stalled or refused to turn over documents. An investigation of Deloitte's Ahold audit may show how effective the new law is in helping U.S. regulators investigate accounting problems.

"That is a crucial change which will have an enormous impact," said Paul R. Berger, SEC associate director of enforcement. "You need to be able to talk to auditors. They're a window into the company. If you don't have the papers, you're at a disadvantage."

Deloitte, whose spokesman would not comment yesterday, has said it "expects to cooperate" with government investigations. Accounting firms sometimes have been reluctant to turn over work done in foreign offices, citing concerns about client confidentiality. They also said sometimes that they had little control over the operations of the foreign arms of their accounting firms.

Deloitte Touche Tohmatsu employs more than 100,000 people in more than 140 countries. Each of its national branches operates as a separate legal entity; Deloitte & Touche LLP is its U.S. unit. Deloitte auditors in the United States and the Netherlands worked on the Royal Ahold account, with U.S. auditors handling the work of its U.S. Foodservice Inc. subsidiary and Dutch accountants handling the Royal Ahold parent company.

Ahold said Monday that it had overstated profits by $500 million or more in the past two years and had fired its chief executive and its chief financial officer. It said it had found accounting irregularities at U.S. Foodservice, in Columbia, Md.

Countries have widely varied accounting standards, and many foreign auditors and regulators have fought efforts by the United States to impose its rules on them. That has created problems for U.S. regulators and investors as more companies operate globally and more auditing is done by just a few international accounting firms, U.S. prosecutors and SEC officials said.

The issue was again highlighted by the Ahold scandal, which some accounting experts said is a prime example of why companies that trade on U.S. exchanges, and their auditors, must be subject to American accounting rules.

"There's all this talk about how international accounting standards are better," said Charles W. Mulford, an accounting professor at the Georgia Institute of Technology. "When I hear that it just makes me sick to my stomach because I think it's so wrong. There's more flexibility in the international standards. It makes it where it's easier to do the kinds of things you want to do. . . . If they want to hide it, they're going to hide it."

Rene Ricol, president of the International Federation of Accountants, which has members in 113 countries, said his group has not taken a position on whether foreign auditors should register with the new U.S. accounting board. He said the federation instead is pushing for "more clarity" in accounting standards worldwide "so people cannot manipulate them."

Some foreign auditors, arguing for exemption from U.S. regulation, have said their rules are better suited to their corporate structures and local practices, and thus better designed to detect accounting irregularities.

Registration with the U.S. board would be a first step for foreign auditors. The board, which is just beginning work, will decide later whether audit firms that register will have to follow only some of the board's rules or will be subject to inspections by the board and detailed investigations.

Securities regulators say the Sarbanes-Oxley Act will change the way accounting is investigated. In some of the biggest corporate accounting scandals, including those involving Xerox Corp. and the Bank of Credit and Commerce International, auditors fought mightily to avoid handing over work papers and other documents to regulators, accounting experts said. Such documents can lay out a paper trail, telling investigators what steps auditors took and whether they did their jobs properly.

SEC lawyers sometimes -- but not always -- got around that problem by making deals with local authorities or leaning on the U.S. branches of global accounting firms.

Regulators went one step further with KPMG, which audited Xerox. SEC lawyers went so far as to issue a "border watch" for an official in KPMG's branch in Mexico, according to people familiar with the investigation. When the KPMG executive entered the United States, the Customs Service notified the SEC and the executive was served with a subpoena for Xerox documents and told that if he did not comply, he could not cross the border. He turned over the documents, two sources said. Xerox settled with the SEC for $10 million last year.

George Ledwith, a spokesman at KPMG LLP, the auditing firm's U.S. branch, said he could not comment on the Xerox matter because of a pending SEC civil fraud lawsuit against KPMG and four of its partners who worked on the Xerox account. "We've always cooperated with the SEC in regulatory and enforcement matters and we will continue to do so in accordance with our obligations," Ledwith said.

One well-known fight involved Price Waterhouse (which has since become PricewaterhouseCoopers), which audited the Bank of Credit and Commerce International before the bank collapsed in 1991, resulting in billions of dollars in losses by investors. After a Senate committee sought documents from Price Waterhouse's offices in England, the company's U.S. arm said the British partnership did not do work in the United States and thus should not be subpoenaed.

Price Waterhouse put forth an argument that has been made repeatedly by many international auditors in recent years: The firm's American offices have no control over auditing branches elsewhere and they maintain separate finances and stores of documents.

Steven Silber, a spokesman for PricewaterhouseCoopers, called the BCCI case "ancient history" and said that since Price Waterhouse and Coopers & Lybrand merged in July 1998, "each time the SEC has asked us for foreign work papers, we've cooperated in trying to obtain them. We just haven't had a dispute with any of our member firms on this issue."