Motorola Mobility Holdings Inc sold slightly fewer smartphones than expected in the fourth quarter and forecast a net loss in the current quarter, as it faces new competition from the Apple Inc iPhone, sending its shares down 6 percent.

In the last full quarter before Motorola's most important customer Verizon Wireless, starts selling the iPhone in February, Motorola's shipments of 4.9 million smartphones were a touch below expectations for 5.2 million smartphones for six analysts contacted by Reuters.

Motorola Mobility, which sells television set-top boxes, as well as handsets, expects to post a first-quarter net loss per share of between 9 cents and 21 cents.

The company had already warned its handset profitability would come under pressure this quarter, but Avian Securities analyst Matthew Thornton said the outlook was a bit worse than he expected. He was also disappointed with the company's quarterly profit and its smartphone sales.

The stock has had a good run so people are going to take it out back and beat it up a little unless they say something good on the call about full year guidance, Thornton said.

In its first quarterly report as a separate company, Motorola said on Wednesday it posted a profit of $80 million, or 27 cents per share compared with a loss of $204 million, or 69 cents per share in the year-ago quarter before it became a stand-alone company.

Excluding unusual items, Motorola said its earnings would have been 37 cents per share, but Thornton said the number was lower than he expected.

Smartphones were a little bit light. Earnings quality in the quarter was a little light and the bottom line guidance for the first quarter was a little light, he said.

Revenue rose to $3.4 billion from $2.8 billion in the year ago quarter, in line with the expectations of at least two analysts. About $2.4 billion of its revenue came from the handset business, Motorola said.

Including smartphones and less advanced phones, Motorola shipped 11.3 million phones in the quarter, which compared well with analyst expectations for 10.7 million.

But investors are most anxious about its success with smartphones because the company has revamped itself after years of market share losses to focus mostly on offering smartphones based on Google Inc's Android software.

The company's shares fell to $32.70 in late trading after closing at $34.83 on the New York Stock Exchange. The stock has already risen 5 percent since January 4, the stock's first official trading day on the New York Stock Exchange.

Motorola Inc split in two in January to form Motorola Mobility and Motorola Solutions Inc . Verizon Wireless is a venture of Verizon Communications Inc and Vodafone Group Plc

(Reporting by Sinead Carew; editing by Andre Grenon)