Apple Inc., Research In Motion Ltd. and six other companies that use Samsung Electronics Co. memory chips were named in a U.S. trade complaint that seeks to block imports of products including the iPhone and BlackBerry Storm.

Closely held BTG International Inc. of West Conshohocken, Pennsylvania, claims Samsung's Nand flash-memory chips, which store songs or pictures on portable electronics, infringe five BTG patents. In a complaint filed today with the U.S. International Trade Commission in Washington, BTG seeks to stop imports of Samsung chips and any products that use them.

The patents relate to ways of programming and reading flash-memory cells that store more than a single bit of information per cell, called "multi-level cell," according to the complaint. That reduces the cost of flash memory and allows consumers to buy cameras that can store more pictures.

Samsung's chips are used in Suwon, South Korea-based Samsung's own products including mobile phones, camcorders, notebook computers and MP3 players, according to the complaint.

They're also used in the Apple iPhone, iPod music player and MacBook Air notebook; Research In Motion's BlackBerry Storm mobile phone; and Sony Corp. digital cameras, Vaio computers and MP3 players.

Also targeted are computers by Asustek Computer Inc., Dell Inc. and Lenovo Group Ltd., and flash-memory cards by PNY Technologies Inc. and Transcend Information Inc.

BTG, which doesn't make any products, licenses its patents to another company, according to the complaint.

The ITC is responsible for protecting U.S. markets from unfair trade practices, including patent infringement. In an unrelated case, the agency is considering whether companies that don't make products should be limited in their ability to file trade complaints.

Marshall, Texas

BTG filed a patent-infringement complaint against Samsung in federal court in Marshall, Texas, in December. Earlier this month, it filed a complaint in Marshall against the companies whose electronics use Samsung flash-memory chips.

Susan Lundgren, a spokeswoman for Cupertino, California- based Apple, and Jess Blackburn, a spokesman for Round Rock, Texas-based Dell, had no comment on the complaint. Officials with Samsung, Research In Motion, Sony and Lenovo didn't immediately return messages seeking comment. Officials with Asustek, PNY and Transcend couldn't be reached after regular business hours.

The complaint is In the Matter of Certain MLC Flash Memory Devices and Products Containing Same, 2673, U.S. International Trade Commission (Washington).