SEOUL (Reuters) - Seoul shares inched down from previous session's 5-1/2 month closing high on Monday morning, as profit-taking by local institutional investors offset foreign net inflows while the won firmed modestly.

The Korea Composite Stock Price Index (KOSPI) was down 0.3 per cent at 2,012.12 points as of 10.43am Singapore time. On Friday, it closed at its highest level since Dec 2.

Kakao, the operator of South Korea's dominant mobile messenger service Kakao Talk, on Monday said it will merge with the country's No. 2 Internet portal Daum Communications in a back door listing.

That development pushed down shares of Naver, the country's biggest Internet portal operator and owner of mobile messenger operator Line, by 3.9 per cent on concerns over intensifying competition.

But aside from the merger news, "the market is showing no major movements," said Kim Byung-yeon, an analyst at Woori Investment & Securities.

The main index will likely be trapped between 2,000 and 2,050 "as investors seek more evidence of improving global demand, thus some strong earnings from local exporters," he added.

Near mid-session, foreign investors were net buyers of 28 billion won (S$34.2 million) of KOSPI shares near mid-session while local institutional funds sold 47 billion won.

Through Friday, foreigners were net buyers for nine consecutive sessions, bringing in nearly 2.5 trillion won.