Sony (NYSE: SNE) Ericsson (NSDQ: ERIC), the world’s fourth largest handset maker, is entering the highly competitive South Korean handset market. It has partnered with domestic carrier SK Telecom (NYSE: SKM) and launched today with a version of its Xperia X1 smartphone that has been pre-loaded with the full version of the hit film Spiderman 3.

Despite the fact that global handset sales are shrinking, and that phone sales in South Korea are dominated by domestic and global handset giants LG (SEO: 066570) and Samsung, Sony Ericsson’s Korean marketing head Han Younhee told Dow Jones the company had “prepared the right products and have met the right partner, SK Telecom.” Han conceded that although the “economic climate isn’t favorable,” the company saw their entry into South Korea as a mid to long term opportunity, “especially when the smartphone business is expanding.” At the launch, Sony Ericsson’s Asia-Pacific head Hirokazu Ishizuka also said Sony Ericsson still expects to return to profit in the second half of the year, though did not disclose how the struggling handset vendor expected to do this. In a statement, Sony Ericsson said it saw handset sales shrinking by 5 percent this year, but that it was still aiming to become one of world’s top three largest handset maker’s by 2011.

More on Sony Ericsson’s chances after the jump.

South Korea has been a tough market to crack for foreign handset makers. Sony Ericsson’s has tried to localize its product by ensuring that several of the application panels on the Xperia X1’s main screen include access to local services such as the domestic Daum web portal and to SK Telecom’s mail and Web services, according to PCworld. HMC Investment Securities analyst Lee Nam-ryung remains skeptical. He told Dow Jones (NYSE: NWS), “Unless the price of the phones is significantly lower than other Korea-made products, it will be hard for the company to get a big share of the local market as was proven by Nokia (NYSE: NOK) and Motorola.”

Still, more foreign makers may be joining Sony Ericsson; April marks the month that a rule that used to require all internet-enabled phones on the market to support the local WIPI (wireless Internet platform for interoperability) standard will be lifted. The ruling was often cited as an entry barrier to foreign phone makers, but with its removal, more global vendors are expected to re-enter the market.