(Reuters) -The U.S. Commerce Department on Wednesday asked a group of anonymous domestic solar manufacturers for additional information before it would consider a request to impose duties on panels produced in three Southeast Asian countries.

This delay delays the expected department decision this week.

U.S. Solar project developers have protested against Commerce investigating new tariffs. The probe, they claim would draw attention to foreign solar producers as well as cripple one nation’s fastest growing sectors.

Timothy Brightbill wrote to the Department, stating that it had given the deadline of Oct. 6, for American Solar Manufacturers Against Chinese Circumvention’s to reply to its set of questions.

The department asks the members of this group to provide their names.

According to the department, a decision would be made within 45 days after receiving an answer.

Brightbill has not yet responded to my request for comment.

U.S. The U.S. Solar Energy Industries Association was the leading U.S. trade organization for solar energy. It expressed disappointment that the department didn’t reject the petition.