Lisa Rapaport
and Scott Moritz
Bloomberg News

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 Tuesday priced at $799 for a Wi-Fi version and $929 for a device that also offers a cellular connection, Apple said.

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,” said Tavis McCourt, an analyst at Raymond James & Associates.

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.

Apple said the added memory will be especially useful to businesses that use heavy amounts of data and need more storage. The iPad is popular for blueprints, training videos, service manuals and X-rays.