President Bush's nominee to an appellate judgeship acknowledged missing the appearance of a conflict of interest in four cases in which he is accused of ruling on litigants in whose companies his family held stock.

Terrence Boyle, Bush's pick for the 4th Circuit Court of Appeals in Richmond, Va., said Wednesday that his aides' routine screening of cases for conflicts of interest "missed" the appearance in these instances.

"These situations were an oversight, an inadvertent mistake," Boyle wrote in a letter responding to questions by Senate Majority Leader Bill Frist, R-Tenn., and Judiciary Committee Chairman Arlen Specter, R-Pa.

"Accordingly, I unknowingly and unintentionally participated in these cases while I held a minimal number of shares in one of the parties," Boyle added. "Whatever minor financial interest I may have had in the case in no way affected my decision-making or the outcome of the case."

Boyle added that since the allegations were first raised in a story on Salon.com, he has substituted an electronic screening process for the manual process.

The stock holdings in question were 10 shares of CSX Corp., 25 shares of America Online, and 50 shares of General Electric Co.

"I regret that the oversight occurred," Boyle wrote. "It certainly was not my intention to participate in a case where I held stock in one of the parties."

It was not clear that Boyle's letter had improved his prospects for confirmation. Democratic leader Harry Reid of Nevada has said his party would filibuster Boyle's nomination if it came to the floor. Specter has not indicated how he would vote or whether to have hearings, saying he wanted to first receive Boyle's answers. And Frist, who earlier this year had promised to confirm Boyle before Congress adjourns, has not scheduled a vote.