Stock prices of three San Diego companies...

Stock prices of three San Diego companies plunged in the last week, the result of negative news, according to Irving Katz, director of research at San Diego Securities.

Cohu, which Monday reported an expected fourth-quarter loss and a drop in year-end earnings, closed the week down 2 3/8. The stock dropped 2 1/8 on Monday alone, Katz said.

Western Health Plans was down 1 3/8 to a new low and a drop of 30% for the year, an example that “excuses aren’t a substitute for earnings,” said Katz.

International Totalizator Systems stock reacted to the company’s losing the California Lottery contract, closing down 1 5/8 to 7 5/8.

Intermark hit a new high of 18 1/8, with analysts anticipating that the company’s acquisition of Fuqua Industries’ 20% interest in Triton Group Ltd. will be just as successful as its purchase from Fuqua of Pier One.

Allied-Signal stock hit a new high of 51 1/2, as some Wall Street analysts valued the company’s stock at $60 per share, which includes the Henley Group spinoff that will operate out of Signal’s old digs in La Jolla.

PSA stock dropped 1 1/2 for the week as the airline operations lost money, victim of continuing air fare wars.

SDG&E; hit a new high of 31 as the Dow Jones utility average marched to new heights.

Southwest Bancorp hit a new high of 4 1/2 as company officials took to the road and spoke to analysts in Los Angeles and San Francisco last week.

Cousins rose 1 to 5 5/8, apparently a delayed reaction to the name change of its retail stores from The Brick Warehouse to Furnishings 2000, Katz said.

Maxwell Labs rose 1 3/4, after an increase in quarterly earnings, and Molecular Biosystems hit a new high of 5 1/2 after publication of a study involving its new enzyme-based AIDS test.