A lobbyist for big business on Wednesday vowed to continue challenging the constitutionality of the Sarbanes-Oxley Act, a 2002 anti-fraud law, after a federal judge dismissed a lawsuit the group brought against the independent board Congress created to oversee the accounting industry.

The Free Enterprise Fund, which filed the suit in February 2006, argued that the Public Company Accounting Oversight Board violates the Constitution’s mandated separation of powers among the three federal branches because its five members are not appointed by the president, cannot be removed by him and Congress does not control the board’s budget.