In New York, the active May COMEX contract firmed 5.20 cents to settle at $3.9315 per lb on Thursday, closer to the upper end of its $3.8485 to $3.9370 session range. Volumes were thin on the first trading day of the new month. A little more than 51,400 lots traded in late New York business, nearly a third below the 30-day average, according to preliminary Thomson Reuters data.