Apple Inc. debuted an iPad with twice the memory of older models, offering users more space to store movies, videos and books amid mounting competition in the tablet market.

The new iPad with 128 gigabytes of storage will be available starting Feb. 5 priced at $799 for a Wi-Fi version and $929 for a device that also offers a cellular connection, Cupertino, California-based Apple said Tuesday in a statement.

Apple bolstered its product lineup in October with the iPad mini, priced from $329 to $659, and a fourth-generation iPad that costs $499 to $829, depending on the features. The latest iPad model comes as Apple works to fend off challengers from Google Inc. and Samsung Electronics Co. in the market for tablets, which NPD DisplaySearch has estimated will more than double to $162 billion by 2017.

“The tablet market is expanding, and Apple sees a market opportunity, not just at the low end but also in the high end with heavy media consumers,” Tavis McCourt, an analyst at Raymond James & Associates, said in an interview.

Through Monday, Apple stock had lost 15 percent this year.

Earlier this month, Apple posted the slowest profit growth since 2003 and the weakest sales increase in 14 quarters, fueling concern about chief executive officer Tim Cook’s ability to keep producing hit products more than a year after the death of co-founder Steve Jobs.

’120 Million Sold’

“With more than 120 million iPads sold, it’s clear that customers around the world love their iPads, and every day they are finding more great reasons to work, learn and play on their iPads rather than their old PCs,” said Philip Schiller, Apple’s senior vice president of marketing, in the statement.

Apple said the added memory will be especially useful to businesses that use use heavy amounts of data and need more storage capabilities. The iPad is used for storing project blueprints, training videos, service manuals, X-rays and other data-heavy files. Nearly all Fortune 500 companies are using the iPad, Apple said.

The more expensive iPad model follows the same strategy Apple employed when its Mac computers were challenged by lower- priced rivals, McCourt said.

“This is Apple logic,” he said. “When cheap netbooks were popular and taking over, Apple upgraded, rebranded, and raised the price of their MacBooks.”

Apple could apply this same high-end strategy to the iPhone with future models of the handset, McCourt said.