Motorola Mobility Holdings Inc., the maker of cellphones and cable set-top boxes that split off from the rest of Motorola in January, is struggling to continue its turnaround and find a stable foothold in the world of smartphones and tablets.On Thursday, it posted a loss for the latest quarter and forecast earnings for the current quarter well below analyst expectations, sending its shares down.The Libertyville, Ill., company stayed optimistic about full-year results, but to reach its goals it has a lot of catching up to do in the holiday season.Motorola shares fell 80 cents, or 3.5 percent, to $22.11 in extended trading after it reported its quarterly results. That's approaching $20.77, the lowest level since the company split from the old Motorola Inc. on Jan. 4. In the regular session, the company's shares lost 89 cents, or 3.7 percent, to $22.91.Motorola shipped 4.4 million smartphones in the quarter, an increase from 2.7 million a year earlier. Some analysts were looking for a higher number to prove Motorola can hold its own against bigger competitors like Apple Inc. and Samsung Electronics.Latin America and China were the bright spots, and sales of regular phones there helped Motorola ship a total of 11 million phones, representing the second year-over-year increase since Motorola's fortunes started a precipitous slide in 2006. Apple shipped 20.3 million iPhones in the quarter.Motorola posted a loss of $56 million, or 19 cents per share, for April through June. That compares with a profit of $80 million a year earlier.Excluding the costs of stock-based compensation and amortization of intangible assets, Motorola turned a profit of 9 cents per share, 2 cents more than analysts expected, according to FactSet.Revenue was $3.34 billion, up 28 percent from $2.61 billion a year ago. That beat analyst forecasts for $3.14 billion.For the third quarter, Motorola expects adjusted earnings to range from break-even to 10 cents per share. Analysts were looking for 27 cents per share.CEO Sanjay Jha said third-quarter earnings would be held back by the delay of the Droid Bionic, Motorola's first phone for Verizon's new "4G" wireless data network; by lower prices and lower volumes of tablet computers; and by a seasonal slowdown in sales of set-top boxes.Motorola launched its first tablet, the Xoom, in February. It hasn't come close to matching the popularity of Apple's iPad, and Motorola cut the price on it recently.By the holiday season, Motorola will have at least one more 4G smartphone and two more 4G tablets, Jha said.For the full year, Motorola expects earnings of 48 cents to 60 cents per share, implying fourth-quarter earnings of 37 cents per share to 59 cents per share. That range straddles the average analyst estimate of 47 cents per share.Last week, Motorola shares jumped after activist investor Carl Icahn disclosed that he's pushing the company to squeeze profits from its vast patent portfolio. Icahn owns 11.4 percent of Motorola and successfully prodded the old Motorola into breaking into two parts to increase shareholder value.Icahn was probably inspired by the pledge from a consortium that included Apple Inc., Research In Motion Ltd., Microsoft Corp. and Sony Corp. to pay $4.5 billion for a collection of 6,000 patents from Nortel Networks, a bankrupt Canadian maker of telecommunications equipment.Motorola has more than 17,000 patents on phone technology, or nearly three times more than Nortel, yet its market capitalization is just 50 percent higher than $4.5 billion. That raises the prospect of some well-heeled company or consortium snapping up Motorola for the sake of its patents alone, or that the company could me more aggressive about licensing it collection.There's a scramble for patents by technology companies as they seek to shore up their litigation defenses. Nearly every maker of smartphones is suing another manufacturer over patents.On Thursday, Jha said the company is already monetizing its patents "very well" over the past few years. But he's "not opposed" to more drastic measures of unlocking their value, he said in an interview, without giving any examples.