Aspen Technology Inc, the process control software house from Cambridge, Massachusetts, asked for its shares to be temporarily suspended from trading on the Nasdaq exchange on Friday pending clarification of its first quarter preliminary results. The company cited an unexpected shortfall in both revenues and earnings, saying that a full statement would be issued before the commencement of trading on Monday. The request to halt trading came mid-way through Friday afternoon after extremely heavy trading had pushed the share price down by 38% to $14.81. Aspen has more than trebled in size over the past three years. It sells its process design software into sectors such as the pharmaceutical and petroleum industries.