Samsung Electronics (Seoul: 005930) started shipping its $499 Galaxy Note 10.1 tablet in a bid for market share against the iPad from Apple (Nasdaq: AAPL), the world's most valuable technology company. On of its innovations is an electronic stylus called the S Pen, first unveiled at the International Consumer Electronics Show in January.

The Korean electronics giant is using the older version of the Android OS from Google (Nasdaq: GOOG), Ice Cream Sandwich in the Galaxy Note 10.1, but tweaked it with options to open as many as six special apps from the bottom of the screen. Widgets will summon functions including e-mail, browser, notepad and a function dubbed Polaris Office.

WiFi enabled now, Samsung said upgrades available in the fourth quarter should come with software capable of communicating with 3G and 4G networks.

The shipments come as a jury in U.S. District Court in San Jose, Calif., may be charged as early as Monday to weigh evidence in a bitter patent suit brought by Apple against Samsung, alleging intellectual property infringement. Samsung is a major supplier of components to Apple, of Cuperino, Calif., as well as its bitter competitor in the tablet and smartphone market.

On Wednesday, presiding Judge Lucy Koh urged the two electronics giants to settle their case before she charges the nine-member jury that heard more than two weeks of testimony. "It's time for peace," she said after the sides rested their cases. "I see risks here for both sides."

Apple introduced the iPad in 2010 and started shipping the third version earlier this year. To date, it's shipped more than 170 million, including 17 million just in its third fiscal quarter, ended June 30 for a 68 percent market share, estimates market researcher IDC.

Samsung, which sold only 2.4 million older Galaxy tablets, held a 9.6 percent share, followed by Amazon, which sold 1.25 million Kindle Fire tablets and took a 5 percent share. The total market was about 25 million, a 66 percent jump over last year.

But others have jumped into the market: Google last month started selling the $200 Google Nexus tablet and Microsoft (Nasdaq: MSFT), the world's biggest software company, has said it plans to start shipping its Surface tablet soon. Other electronics companies, including China's Lenovo Group (Pink: LNVGY) and Sony Corp. (NYSE: SNE) have promised major efforts alongside other Taiwanese products from both Asustek (Taipei: 2357) and Acer Group (Taipei: 2353).

As Samsung has started shipping the S Pen, Microsoft's Surface will come with a keyboard to enable more Office-like functions.

Apple, meanwhile, has promised upgrades of the iPad but executives, headed by CEO Tim Cook, have declined to provide details about future products in the company tradition.

The new Samsung tablet is available immediately at leading stores such as Best Buy Co. (NYSE: BBY) as well as through Amazon.com, Fry's and Conn's. Besides the 16GB version priced at $499, Samsung said it will offer a 32GB version for $549.

Samsung Electronics shares closed unchanged at 1.345 million won (US $1,200) on Thursday. In the U.S. Apple shares rose $4.81 to $635.64 in afternoon trading. Amazon.com shares rose $3.87 to $241.28.