Irvine, California-based AST Research Inc warns that it expects to post a first quarter net loss of $39m to $40m on sales of $495m, lower than had been expected: it has received a waiver on its $300m committed bank revolving credit agreement, which covers potential defaults due to its first quarter loss; it is to close its Fountain Valley, California manufacturing facility for personal computers at a cost of about 690 jobs or 10%; the problems in the quarter are a continuation of previously disclosed manufacturing issues such as component constraints and product development delays, the firm said.