Apple Inc. unveiled an updated iPad tablet with a sharper display and faster communications, as it strives to stay ahead of competitors and prove the devices can trump personal computers.

At an event Wednesday in San Francisco, Apple's chief executive, Tim Cook, and his lieutenants unveiled the third iteration of the device, which they simply called 'the new iPad' rather than applying a specific name for the product. It will be available starting March 16 in the U.S. and 10 other countries.

Though slightly thicker and heavier, the device looks and feels much like the current iPad 2. It also has the same starting prices: $499 for the Wi-Fi only models, or $629 for those that also have cellular connectivity. Those devices will now be capable of 4G wireless speeds, which are about 10 times faster than 3G found in the iPad 2.

Rather than lower the price of the latest model to more directly compete with rival tablet makers such as Amazon.com Inc. and Barnes and Noble Inc., Apple continues to count on a variety of technological improvements to appeal to users.

The new iPad's key features include an unusually high-resolution screen, support for the 4G technology known as LTE and a microprocessor chip with more powerful graphics circuitry that helps render realistic-looking videogames.

Apple is also dropping the price of the iPad 2 to a starting price of $399 in an effort to broaden the market. Like the iPad 2, the new tablet will be sold by Verizon Wireless and AT&T Inc.

The new iPad is crucial to Apple's efforts to write its next chapter and wrest more control over the growing number of activities consumers do digitally. First a computer maker that later reinvented the digital-music player and mobile phone, Apple executives now describe the company as an enabler of a broad array of digital devices central to consumers' lives, a message Mr. Cook underscored repeatedly Wednesday.

Mr. Cook, 51, kicked off the event by talking about the 'post PC era' and Apple's dominance of it, highlighting the suite of iPod, iPhone and iPad products. 'The PC is no longer the center of your digital world but rather just a device,' he said.

The event marked the first to launch a new device since the death of Apple co-founder Steve Jobs and the second that Mr. Cook has led since he became CEO in August. Like the latest iPhone announced in October, the changes for the new iPad are largely under the hood and Apple has had to show why they are worth it.

Executives made the case during the event by highlighting the resolution of the new iPad display, which has four times as many pixels as the iPad 2 and more than some high-definition televisions. Apple Senior Vice President Phil Schiller showed off the 4G wireless speed by displaying photos on a big screen that loaded rapidly in an email, and a video clip that began streaming instantly without buffering.

Consumers and analysts seemed impressed with the under-the hood improvements and said that the new iPad should sell well. Piper Jaffray analyst Gene Munster called the changes 'significant' and said it would help the company solidify its lead in the market.

The company's stock price bounced up and down slightly as details about the iPad became known, before finishing the trading day at $530.69, up 43 cents.

During the event, Apple also said that a new version of its $99 Apple TV device that supports higher-resolution video would also go on sale March 16. The box, which provides a way to get Internet video on traditional televisions, also has a new interface and the ability to sync some movies purchased by iTunes across Apple devices.

Since its introduction in 2010, the iPad and related products and services have contributed greatly to the company's booming business, with sales of the devices more than doubling to 15.4 million in its quarter ending in December. Despite numerous contenders, Apple continues to dominate the tablet market, having sold more than 50 million iPads to date.

Meanwhile, rivals like Dell Inc. and Hewlett-Packard Co. have withdrawn rival tablets from some markets and are waiting for a new version of Microsoft Corp.'s Windows operating system expected to go on sale later this year to try again.

While new devices running Google Inc.'s Android operating system, such as Amazon.com's $199 Kindle Fire tablet have drawn solid reviews, sales have been 'modest,' says Toni Sacconaghi, an analyst at Sanford C. Bernstein & Co. IPad competition has been 'lackluster,' he said.