Worldwide sales of mobile phones to end users reached 419 million units in the second quarter of 2012, a 2.3% decline from the second quarter (2Q) of 2011, according to Gartner (www.gartner.com). Smartphone sales accounted for 36.7% of total mobile phone sales and grew 42.7% in the second quarter of 2012, according to the research groupo.

Demand slowed further in the second quarter of 2012, says Anshul Gupta, principal research analyst at Gartner. The challenging economic environment and users postponing upgrades to take advantage of high-profile device launches and promotions available later in the year slowed demand across markets, he added.

 “High-profile smartphone launches from key manufacturers such as the anticipated Apple iPhone 5, along with Chinese manufacturers pushing 3G and preparing for major device launches in the second half of 2012, will drive the smartphone market upward,” Gupta says. “However, feature phones will continue to see pressure.”

In the second quarter of 2012, Samsung’s mobile phone sales were up 29.5% from the second quarter of 2011, and managed to extend its lead over both Apple and Nokia quarter on quarter. This quarter’s growth was driven by record sales of Galaxy smartphones, meaning smartphones now account for 50.4% of all Samsung mobile devices, or 45.6 million units.

Demand for the new Galaxy S3 was particularly strong, exceeding Samsung’s own expectations, with a reported 10 million units reached in the two months after its release, according to Gartner. The Galaxy S3 was the best-selling Android product in the quarter and could have been higher but for product shortages.

In the second quarter of 2012, consumer demand for the iPhone weakened as sales fell 12.6% from the first quarter of 2012, but grew 47.4% year-over-year. Depending on the exact launch date of a new iPhone, Apple might experience another weaker-than-usual quarter in the third quarter of 2012, while Apple will be ready to take advantage of the strong holiday sales in North America and Western Europe that have historically remained immune to economic pressure, says Gartner.

In the smartphone OS market, Android extended its lead with an increase of 20.7 percentage points in market share in the second quarter of 2012. While Apple’s iOS market share slightly grew year-over-year (0.6%), it declined 3.7 percentage points quarter-over-quarter, as users postponed their upgrade decisions in most markets ahead of the upcoming launch of the iPhone 5.

Gartner analysts said the arrival of the iPhone 5 should provide the greatest upgrade opportunity yet as the expected new design with a larger screen and likely other stylistic changes to the form factor will certainly make a strong case for iPhone 4 users to upgrade.