Samsung Electronics Co., Apple's biggest competitor in the market for iPad-sized tablet computers, is updating its line to include a feature that lets a tablet act as a universal remote control for an entertainment center.

The storage space on the new Galaxy Tab 2 will also be expandable with small memory cards.

The tablets will come in two sizes. The 7-inch version, which will cost $250 goes on sale on April 22. The 10-inch version will cost $400 and would be available from May 13.

Apple Inc.'s competitors are experimenting with different tablet sizes and features as they try to come up with a way to challenge the iPad's commanding lead in sales. Toshiba Corp. this week revealed a tablet with a 13-inch screen, putting a laptop-sized screen in a tablet. The iPad has a screen that only measures 9.7 inches diagonally.

According to research firm IDC , IPad accounted for nearly 60 percent of the tablet computers sold last year.

Apple's other closest competitor in the overall tablet market is Amazon.com Inc., but its Kindle Fire is half the size of the iPad and less than half the price, putting it in a somewhat different category. Of the manufacturers that make tablets of the same size and range as the iPad, Samsung has the largest share.

The iPad does not have expandable memory or the infrared diode that will let the Samsung's models control a TV set or cable box. Instead, the new primary feature of Apple's iPad, released last month, is an ultra-high-resolution screen.

The updated Samsung models will not have higher-resolution screens, even though analysts believe Samsung is one of the sources for the new iPad screen.