Hewlett-Packard said Wednesday that two Taiwan-based companies and a Chinese firm had been found to be infringing on patents held by the US computer giant for inkjet print cartridges. HP said the US International Trade Commission (USITC) had upheld an initial ruling in HP\'s favor in June that Asia Pacific Microsystems (APM), a subsidiary of Taiwan-based United Microelectronics Corp., was infringing on HP patents in manufacturing inkjet printheads. In addition, the USITC ruled that MicroJet Technology Co., a subsidiary of Taiwan-based DB-Tel Inc., and China-based PTC Holdings Ltd. are infringing on HP patents in the manufacturing and sale of inkjet print cartridges, HP said. The USITC has recommended that the items be barred from the United States, the Palo Alto, California-based HP said in a statement. The USITC, a Washington-based quasi-judicial federal agency, has the power to bar importation and sale of products found to be infringing on patents. \"HP makes a tremendous investment in developing innovative products for our customers and is committed to pursuing action to protect these innovations and, by extension, the value we deliver to our customers,\" Vyomesh Joshi, executive vice president of HP\'s imaging and printing group, said. \"HP is pleased with the outcome on these matters and the ITC\'s enforcement of intellectual property rights,\" Joshi said.