SAN FRANCISCO — Federal Circuit Chief Judge Randall Rader should explain why he recused from an appeal earlier this month after the court had already issued its ruling, the party that lost the appeal told the court Wednesday.

Acknowledging that it’s “a matter of great sensitivity,” McCarter & English partner William Zucker filed a letter with the U.S. Court of Appeals for the Federal Circuit seeking “full disclosure” of Rader’s reasons, including when during the litigation they became an issue.