Top global cellphone makers are set to report a disappointing quarter, hit by euro zone debt problems and the roaring success of smartphone heavyweight Apple, and new launches may determine how they fare in the year's second half.

BlackBerry maker Research in Motion has already reported disappointing quarterly shipments, rekindling worries it is losing market share to Apple and other rivals. Nokia also issued a second profit warning as it struggles to compete against iPhone.

While smartphones are growing much faster than expected, overall handset growth has softened, said Goldman Sachs analyst Simona Jankowski said in a note.

Q2 handsets will grow only 2 percent sequentially versus our prior estimate of 5 percent growth...although we expect H2 demand to be largely in line with normal seasonal trends.

Overall sales volume growth is expected at 13.8 percent in the second quarter and hit 11.6 percent this year, up from 10.8 percent estimated three months ago, a Reuters poll of 31 banks, brokerages and research firms showed on Wednesday.

EUROPE CRISIS HITS SAMSUNG, LG

South Korea's Samsung Electronics and LG Electronics Inc, the world's No.2 and No.3 handset makers, are expected to show sharply reduced earnings on slumping European sales, a 10 percent drop in the euro last quarter and smartphone delays.

LG is likely to report its struggling handset business has swung to a quarterly loss, while Samsung could show profits and margins nearly halved from the previous quarter.

What LG needs the most right now is a trendy phone that could outsell 10 million units to catch up rivals and gain a foothold in the smartphone market, said Yoon Hyuck-jin, a Shinyoung Securities analyst.

But its existing line-ups are further likely to lose attention as consumers flock to phones like iPhone... Whether it can successfully make a foray into the market will be decided in the fourth quarter when it releases premium phones based on Windows.

Both firms are aggressively preparing for a rebound, with LG rebranding its smartphone models 'Optimus' and planning a global launch of an Android-based model this quarter with 120 carriers worldwide.

Samsung is also betting on strong sales of Google's Android-based 'Galaxy S', its answer to iPhone, to help it treble smartphone shipments this year.

In Q3, Samsung's handset shipments will be heavily influenced by whether European handset sales channels, which have kept inventory levels low in the wake of the European debt crisis, will start stockpiling again, said Daewoo Securities analyst James Song.

APPLE VS OTHERS

From the world's top handset maker Nokia to RIM, most cellphone vendors are struggling to keep up with Apple, which first introduced the hot-selling iPhone in 2007 and ratcheted up competition with a new iPhone rollout last month.

Nokia's profit warning weakened the interest on (shipment) figures. But it will be interesting to see how they will comment on outlook, said Hannu Rauhala, analyst at Pohjola Bank in Helsinki.

Expectations for 2010 sales volumes of most vendors including Nokia, LG, Sony Ericsson and Motorola were revised down as they struggle to offer compelling smartphone line-ups to challenge iPhone.

But Samsung was the sole major vendor with positive forecast revision. Shipment forecasts for Samsung was raised by 5 percent to 272 million units from the previous poll in April.

Samsung has high sales targets for the Android phone and market surveys...show that its success also has been good in mid-range handsets, said Rauhala of Pohjola Bank.

For the April-June quarter, analysts roughly expect Apple, No.3 smartphone maker, sold 8-9 million iPhones in total.

That forecast comes as Apple's iPhone 4 received a poor review from influential consumer guide Consumer Reports.

RIM's BlackBerry shipments topped 11 million units in the three months ending May 29 and it has forecast shipping 11.6 million to 12.1 million devices in the current quarter.

(Editing by Muralikumar Anantharaman)

South Korea Steve jobs Smartphone Apple inc.