Sony released a new version of its Memory Stick Duo card, called the Memory Stick Pro Duo with a capacity of up to 512MB, up from a maximum of 128MB in the previous version. It will theoretically be able to transfer data at a rate of up to 20 megabytes per second under optimal conditions, according to Sony.

"Video streaming is critical for Sony, because digital camcorders will be a strong category in the future, so cards will need faster transfer rates," said Joseph Unsworth, an analyst with research firm Gartner.

Memory Stick Duo cards are smaller versions of Memory Stick cards, about the size of a postage stamp. They are meant to be used in portable devices such as cell phones.

Flash memory card makers SanDisk and Lexar Media announced on Friday that they will begin selling the Pro Duo cards in September. The 256MB Pro Duo cards will cost about $130, and the 512MB cards will cost about $300, according to Sony.

Addressing the emerging camcorder and cell phone markets should help Memory Stick to maintain its No. 2 market share position, behind Secure Digital, in the removable flash memory card industry. In 2002, Memory Stick had 21 percent of the nearly $2 billion worldwide market, which is expected to grow to $4.6 billion in revenue by 2007, according to Gartner.