Briefly

Parker Hannifin Corp. of Cleveland said it acquired Symetrics Inc., a Newbury Park maker of quick-disconnect couplings for the aerospace industry, for an undisclosed amount of stock. . . . Simi Valley-based MICOM Communications Corp., a supplier of data/voice integration networking systems, agreed with AlphaQuest Inc. of Saratoga to jointly market the two firms’ products at trade shows and other marketing events. AlphaQuest provides voice and data communications services. . . . The collapse of the refinancing boom saw real estate lending in Ventura County decline to $1.033 billion in the third quarter, down from $1.192 billion in the second quarter and off 43% from $1.825 billion in the third quarter of 1993.