South Korean consumer electronics giant LG Electronics Inc. saw its net loss widen in the fourth quarter from a year earlier due to increased marketing costs and a one-off TV cartel fine.

Net loss came to 467.8 billion won ($431 million) in the October-December period, growing more than three-fold from the loss of 111.6 billion won the previous year, LG Electronics said in a regulatory filing.

Revenue slipped 2.3 percent on-year to 13.5 trillion won over the cited period, while operating profit jumped 25.2 percent to 107.2 billion won in the cited period.

The weaker bottom line was attributed to growing marketing costs on TV and other products over the holiday season as well as cartel fines imposed by the European Commission.

In December, the European regulator fined LG Electronics and five other firms, including Panasonic and Philips, a total of 1.47 billion euros ($1.98 billion), for fixing prices of now-obsolete cathode ray tubes between 1996 and 2006.

LG, which was fined 697.5 billion won, said around 400 billion won of the fine was reflected in the fourth quarter, while the remainder was set aside earlier. The company has vowed to appeal.

Despite the net loss, LG said sales of its flat-panel TV sales rose 17 percent from three months earlier on the back of robust demand in developed markets.

The company also said its mobile business logged its first annual operating profit in three years thanks to solid smartphone shipments.

LG, a latecomer to the smartphone sector compared with bigger rivals Samsung Electronics Co. and Apple Inc., has been struggling to reclaim its mobile foothold.

The company's mobile communications unit, which covers handset sales, was in the red for six straight quarters between April 2010 and September 2011 and again in the April-June period of 2012 due to increased marketing costs and growing competition from low-end handset makers.

LG said smartphone sales surged 56 percent on-year to a record 8.6 million units in the fourth quarter, buoyed by positive response for its Optimus smartphone line-up in the global market.

Smartphone sales also accounted for more than half of its overall handset sales of 15.4 million for the first time, it added.

The South Korean electronics firm said it plans to ramp up its market share in the global TV and smartphone market via OLED TVs, ultra HD TVs and both premium and low-end smartphones.

LG aims to reap a revenue of 53.5 trillion won this year, up from 51 trillion won in 2012.

It also plans to spend 2.5 trillion won on capital expenditure this year, up from a 1.6 trillion won plan in 2012. The company did not disclose its actual capex spending last year.

Shares of LG Electronics ended at 73,500 won on the main stock index, unchanged from Tuesday's close. (Yonhap News)