Apple Inc plans to use a larger screen on the next-generation iPhone and has begun to place orders for the new displays from suppliers in South Korea and Japan, people familiar with the situation said on Wednesday.

The new iPhone screens will measure 4 inches from corner to corner, one source said. That would represent a roughly 30 percent increase in viewing area, assuming Apple keeps other dimensions proportional. Apple has used a 3.5-inch screen since introducing the iPhone in 2007.

Early production of the new screens has begun at three suppliers: Korea's LG Display Co Ltd, Sharp Corp and Japan Display Inc, a Japanese government-brokered merger combining the screen production of three companies.

It is likely all three of the screen suppliers will get production orders from Apple, which could begin as soon as June. That would allow the new iPhone to go into production as soon as August, if the company follows its own precedent in moving from orders for prototypes for key components to launch.

Apple's decision to equip the next iPhone with a larger screen represents part of a competitive response to Samsung Electronics Co Ltd.

Samsung unveiled its top-of-the line Galaxy smartphone with a 4.8-inch touch-screen and a faster processor earlier this month.

With consumers becoming more and more comfortable using smartphones for tasks they once performed on laptops, like watching video, other smartphone manufacturers have also moved toward bigger displays.

AESTHETICS AND DESIGN

A likely shakeup in the design of a larger-screen iPhone could go a long way in boosting its "wow" factor, convincing fans to trade in their old iPhones for new ones, said Shaw Wu, an analyst at Sterne Agee.

"Not only do users pay for features, but they also pay for aesthetics and design. That's as important, or more important, than features," Wu said. "People love the current design -- but it's 18 months old."

The latest iPhone 4S was introduced in October of last year and essentially has the same form factor as the iPhone 4, launched in 2010.

Samsung, which this year became the world's largest cell phone maker, sold 45 million smartphones in the first quarter, and sales of the Galaxy phones outstripped the iPhone.

Apple was not immediately available to comment.

Apple's move toward a larger display for the next generation iPhone was earlier reported by the Wall Street Journal.

In addition to being Apple's rival, Samsung is also a major components supplier to the U.S. computer, tablet and phone manufacturer.

The share of the production of new screens that go to each of the three manufacturers working with Apple has not been determined, one source said.

Sales of the touch-screen iPhone now account for about one-half of Apple's total sales, and the phone has been a key source of growth for the company in Asia.

A report in March by a South Korea business newspaper said Apple would use a "retina" display on the next iPhone, the same technology in its latest iPad that enhance image quality.

 With investors hungry for Facebook shares ahead of a hotly anticipated offering, the social network unveiled a 25 percent increase Wednesday in the number of shares to be sold at the market debut.

The increase comes from current shareholders, who had previously obtained stock in private offerings, seeking to cash in on the hefty price amid a Facebook frenzy.

"This is definitely in response to very strong global investor demand," said Lou Kerner, founder of The Social Internet Fund.

"US institutional demand has been good; the retail and global demand has been overwhelming."

The move by the Internet giant comes one day after it filed paperwork with the US Securities and Exchange Commission raising its initial public offering share price from a range of $28 to $35, to between $34 to $38 per share.

A definitive price was expected on Thursday.

Facebook will reportedly go public hacker style with an all-night software bending bash to culminate at its new California campus with co-founder Mark Zuckerberg remotely ringing the Nasdaq opening bell.

Employees were signing up for a "hackathon" to start late Thursday at Facebook's offices in the Silicon Valley city of Menlo Park and continued until the social network's initial public offering of stock on Friday, according to tech news websites TechCrunch and All Things Digital.

"Hackathons are a big tradition at Facebook," the company explained on a Facebook page devoted to the events.

"They serve as the foundation for some great (and not so great) ideas," the message at facebook.com/hackathon continued.

Kerner said some Facebook insiders may be seeking to take profits now, because they might otherwise have to wait six months under SEC regulations.

Trading is expected to begin on Friday under the symbol "FB" on the technology-heavy Nasdaq.

There was no immediate explanation for the increase in shares, which will come from the current holders of shares in prior private offerings. The latest document says 421 million shares will be issued, up from 337 million. And that could be raised to 484 million if demand is high.

Under the new share plan, Mark Zuckerberg will hold 55.8 percent of the voting power, down slightly from an estimated 57.3 percent. The 28-year-old controls the firm through a dual class stock structure and certain shares that give him a "proxy" for voting.

The net proceeds to the company will remain unchanged at $6.4 billion, the filing with regulators said.

At the midpoint price, the IPO could net some $16 billion for all the sellers at the latest estimate, and at the maximum price more than $18 billion.

Depending on the final value, the IPO would be one of the largest of a US firm on Wall Street, behind the 2008 offering of Visa ($17.8 billion) and possibly above that of General Motors in 2010 ($15.7 billion).

The IPO share price gives Facebook a value of $93-104 billion.

Based on the estimated market value, Facebook would be in the neighborhood of Amazon ($100 billion) and Cisco ($90 billion), but also ahead of Hewlett-Packard ($45 billion) and struggling Yahoo! ($19 billion).

Some analysts predicted Facebook's stock price will jump quickly as the social network finds ways to leverage its membership of 900 million.

The California giant separately agreed Tuesday to a tie-up with Lightbox, an Android photo app, by hiring its developer team. This follows a $1 billion deal to acquire another photo sharing app, Instagram.

The IPO comes amid a wave of tech offerings with mixed success. Groupon, the online deals firm, has lost 34 percent since its November IPO, while the professional social network LinkedIn has soared 150 percent in a year.

In a negative for Facebook, General Motors said it plans to stop advertising at the network because it determined that paid ads had little impact.

"We are reassessing our Facebook advertising, but we remain committed to very aggressive social media strategies and will continue to push content on Facebook through our product and brand Facebook pages," GM spokesman Patrick Morrissey told AFP.

The US auto giant is the third largest advertiser in the United States, with expenditures of $1.8 billion in 2011, according to Kantar Media.

But the consultancy eMarketer says Facebook's share of overall US display ad market revenues grew to 14 percent in 2011 and will likely hit 16.8 percent this year, overtaking Google.