GENEVA (AP) _ The chief of Switzerland's largest bank vowed Saturday not to resign, despite international criticism over his bank's role in the controversy over missing Holocaust-era accounts.

Robert Studer, president of Union Bank of Switzerland, told the Zurich daily Tages-Anzeiger he had been the victim of a campaign to taint his name and said he had no intention of stepping down.

``I have no reason to,'' he said.

Studer has been criticized for publicly questioning the motives of whistle-blower Christoph Meili, the UBS night watchman who fled to the United States earlier this year.

The guard, who lost his job over the case, took his wife and two children to New York because of anonymous threats made after he salvaged Holocaust-era documents from the bank's shredder room.

Studer, who also gave broadcast interviews Saturday after months of silence, stopped short of apologizing to Meili, but said he regretted that Meili left Switzerland. He also deplored the destruction of documents.

Leading the campaign for Studer's resignation has been his longtime opponent, Martin Ebner, a major shareholder of UBS who has been conducting a legal battle to overthrow the bank's management.

For years, Ebner has criticized UBS's management for failing to produce sufficient profits. Studer claims Ebner is exploiting the bank's current problems over dealings with the Nazis and Holocaust victims.

Studer said Ebner is orchestrating a defamation campaign in demanding his resignation. He didn't elaborate.

UBS and other major Swiss banks have been hit by a torrent of criticism over their activities during World War II. Jewish groups in particular have accused the Swiss of serving as the Nazis' bankers and of concealing the assets of Holocaust victims.

New York City authorities recently barred UBS from taking part in a deal to underwrite federal and state aid payments to the city.

New York Comptroller Alan Hevesi cited the treatment of Meili, UBS's shredding of World War II-era documents and its public denial that the documents were important.

Studer said sanctions by New York and by California, which put a moratorium on dealings with all Swiss banks, had not had a great effect on UBS' business.

UBS and other Swiss banks have embarked on a major campaign to make up for any wrongdoing. They are giving heirs of Holocaust victims easier access to any accounts and have contributed to a multimillion-dollar fund to aid needy survivors of Nazi atrocities.

Switzerland also has set up an international committee of independent historians to delve into previously secret government archives and lay out exactly what happened before and during World War II.