A prominent lobbying firm has dropped Toyota as a client after realizing that representing the besieged automaker posed a conflict with another customer, the State Farm insurance company.

J. David Hoppe, president of Quinn Gillespie & Associates, said the firm learned another client "was in a position adverse to Toyota" and stopped representing Toyota Friday.

Hoppe would not identify the other client. An auto industry official, speaking on condition of anonymity to reveal confidential information, said the other client was State Farm, the country's largest auto insurer.

State Farm has said it told federal regulators in 2007 about reports of unexpected acceleration in Toyotas — one reason the company has recalled vehicles.