SANTA FE, N.M. (AP) — Avangrid, a U.S. subsidiary of global energy giant Iberdrola, has been ordered to explain why it withheld information in a merger case about penalties stemming from customer service complaints in other states. An official with the New Mexico Public Regulation Commission issued his order Monday. Critics have said the questions about customer service are relevant because the performance of Avangrid’s utilities elsewhere gives an indication of how Avangrid would perform if a merger with Public Service Co. of New Mexico is approved. The multibillion-dollar deal would give the Connecticut-based company more than a half-million customers and access to a network of transmission lines and other infrastructure.