South Korea's LG Electronics said its net loss in the fourth quarter quadrupled from the previous year due to higher marketing costs, a stronger won and a one-off TV cartel fine.
The company said it lost 467.8 billion won ($431 million) in the October-December period, compared with a 111.6 billion won in the same period the year before.
Consolidated revenue fell 2.3 percent year-on-year to 13.5 trillion won, while operating profit rose 25 percent to 107.2 billion won.
In the fourth quarter, the country's second-largest mobile phone maker saw robust shipments of flat-panel TVs and smartphones, but the bottom line was eroded by growing marketing costs.
It was also hit by a fine of $653 million imposed by the European Commission in December for price-fixing.
LG, the world's second-largest flat-screen TV maker, said sales of flat-panel TVs hit a record high 9.3 million units in the three months to December, while its handset unit saw its first annual operating profit in three years thanks to solid smartphone shipments.
LG said smartphone sales in the fourth quarter surged 56 percent from a year ago to a record 8.6 million units.
The company has rolled out a series of new models seeking a bigger share of the lucrative smartphone market where it has lagged rival Samsung Electronics for years.
Its home entertainment business had the strongest quarter of the year in terms of revenue, but profitability was hit due to lower average selling prices and increased competition.
This year LG plans to increase smartphone revenues and market share by launching new models.
It has targetted total revenue of 53.5 trillion won in 2013, up from 51 trillion won last year.