WHEN ADVANCED MATRIX Technology Inc. was ready to produce its new line of printers, it did something many manufacturers are doing nowadays. It teamed up with an offshore partner, Singapore-based Lam Soon, which could help hold down production costs. But Advanced Matrix got something else, too: lots of money from Lam Soon, which became the new majority stockholder in the cash-poor company.

While many foreigners are purchasing Treasury securities, some Far Eastern concerns are buying into U.S. enterprises. "I'm getting several business plans a week, most of which are not even solicited," says Eldridge Wood, president of Inter-Pacific Capital Corp., which handled the Lam Soon deal. "By owning part of an American business, [foreign companies] realize they will have access to continuing R&D developments. For U.S. companies, it means a source of funds that is different from venture capital."

The list of foreign buyers -- many of them family-owned businesses -- seems to grow every month:

* Eric Tang, of Hong Kong, took a "major" equity position in Vector Graphic Inc., a troubled computer maker.

* Ching Fong Investments USA, an affiliate of Ching Fong Investments Ltd., of Taiwan, bought Magnex Corp., a maker of disk-drive parts.

* The Mellow Group, of Taiwan, is buying a minority interest in Osborne Computer Corp.

Family-owned companies, though, are often slow-moving. "There's no doubt the young executives want to diversify," says Bill Wells, an attorney with Graham & James, specializing in foreign investments. "But they still go back to their fathers, who tell them, 'Watch out."