GM Daewoo Auto & Technology Co., the South Korean unit of General Motors Corp. (GM), Tuesday posted a net loss in 2008 due to low demand and investment losses.

GM Daewoo's Vice President Jay Cooney said by phone that high oil prices last year led to reduced sales of SUVs, while rising manufacturing costs and volatile foreign exchange rates took their toll on profits.

GM Daewoo shifted to a net loss of KRW875.69 billion ($663 million) last year from a net profit of KRW540.51 billion a year earlier, the company said in a regulatory filing.

Losses from derivative investments jumped to KRW2.33 trillion last year from KRW206.45 billion a year earlier, said the filing.

Before last year, the carmaker had achieved three straight years of full-year net profit from 2005-2007.

Full-year operating profit plunged 39% to KRW290.31 billion in 2008 from KRW472.27 billion a year earlier, while sales were down 1.6% to KRW12.310 trillion from KRW12.514 trillion.

GM Daewoo, which said it may suffer liquidity problems in the second quarter, is in talks with the Korean government on a daily basis to secure short-term financial support.

Its exports plunged by 45% on year to 116,913 units in the first quarter and domestic sales fell 34% to 18,576 units.

GM and GM's affiliated companies own a 72% stake in GM Daewoo, while Korea Development Bank has the remaining 28%.

-By Kyong-Ae Choi, Dow Jones Newswires; 822-2198-2236; kyong-ae.choi@dowjones.com