Samsung SDI Co., the battery-making unit of Samsung Group, said Monday its net loss widened in the fourth quarter of 2015 from a year earlier.

The net loss came to 231.3 billion won (US$194 million) in the October-December period, worsening from the net loss of 128.8 billion won posted a year earlier, Samsung SDI said in a regulatory filing, without giving reasons for the on-year fall.

It was also a sharp turnaround from a net profit of 502.4 billion won in the third quarter. The on-quarter drop was attributed to falling seasonal demand.

Fourth-quarter sales edged down 2.53 percent on-year to 1.86 trillion won. The company also posted an operating loss of 80.8 billion won, compared to an operating profit of 37.2 billion won a year earlier.

For all of 2015, Samsung SDI posted a net profit of 25.6 billion won, compared to a net loss of 80.3 billion won in 2014.

Samsung SDI, however, posted an operating loss of 59.8 billion won, compared to an operating profit of 70.8 billion won a year earlier.

In the fourth quarter, the battery business posted sales of 848.4 billion won, down 4.3 percent from a quarter earlier.

Sales of the electronics material business also shed 5.6 percent to 409.1 billion won. Its chemical business, which will be sold to Lotte Group this year, posted sales of 603 billion won, down 10.8 percent from the previous quarter.

Samsung SDI said the overall on-quarter decline was attributable to falling seasonal demand, especially for products used in small information-technology devices.

In 2016, Samsung SDI said it expects the market for smaller batteries for electric vehicles (EV) and power tools to expand, adding China's demand for EVs and energy storage system (ESS) products. The ESS refers to the procedures that a large-scale battery uses to efficiently distribute power.

Shareholders of Samsung SDI agreed on Monday to hive off its chemical division, tentatively named SDI Chemical, next month and eventually sell its 90 percent stake to Lotte Chemical Corp. by the end of the first half.

Samsung SDI said it plans to revitalize its performance by streamlining its business portfolio and focusing on the batteries for electronics vehicles.

Shares of Samsung SDI closed 0.49 percent higher at 102,500 won, while the market added 0.74 percent. The fourth-quarter result was announced after the market closed Monday. (Yonhap)