LG Electronics said Wednesday it climbed back into the black in the final quarter of last year, posting 13.81 trillion won in sales and 23.1 billion won in operating profit.

The sales figure for the fourth quarter is a 7 percent increase from the third quarter backed by the positive sales of smartphones which run on the fourth generation Long Term Evolution network.

In a regulatory filing, the company also said that its total sales recorded 54.25 trillion won in 2011, a drop of 3 percent from 2010, but the operating profit figure rose 58.9 percent compared to the same period, reaching 280.3 billion won.

LG’s mobile communications unit recorded 2.77 trillion won in sales and 12 billion won in operating profit in the fourth quarter.

The total number of shipped handsets was 17.7 million units, down 16 percent from the third quarter, however, the firm was able to get back into the black for the first time in the past seven quarters.

“Although the number of feature phones decreased in size in terms of sales last year, there was a meaningful change in that we released premium handsets such as the Optimus LTE,” said LG’s chief financial officer Jung Do-hyun during its earnings briefing at its headquarters in Yeouido. “The Optimus LTE was well-received in the market because of its competitiveness in picture quality and design, contributing to the improvement in profit figures.”

LG’s home entertainment unit also showed strong sales, reaching 6.31 trillion won in sales and 149.7 billion won in operating profit from October to December.

The unit, in charge of television sales, saw its sales grow about 18 percent in overseas markets, including North America, Europe and Central and South America, in the final quarter compared to the third quarter, added on to the fact that it was the industrial peak holiday season.

The number of flat screen TVs sold recorded 8.8 million units, which is its biggest quarterly figure ever.

The firm’s home appliance unit saw its sales increase 7 percent last year compared to 2010, but the air-conditioning and energy solution unit experienced a dip in sales in the fourth quarter compared to the same period in 2010 due to the sluggish global economy, especially in Europe, LG officials said.

For this year, LG has set its sales target at 57.6 trillion won with plans to inject about 4.2 trillion won as investment to nurture future growth projects.

Its target comes as TV sales are expected to rise with the 2012 London Olympics and the end of analog broadcasts in the country as well as a stronger lineup of LTE smartphones.

With the largest-ever investment put into research and development, the company also plans to focus on projects involving water management, light-emitting diodes and healthcare, its officials said.

By Cho Ji-hyun (sharon@heraldcorp.com)