Seoul stocks eked out modest gains Tuesday, as corporate buying helped the KOSPI hold above 6,800 despite net selling by retail, foreign and institutional investors. The benchmark index opened at 6,784.29, down 0.52 percent from the previous session, and extended its losses early in the day before gradually recovering to trade around the flat line. It ended at 6,835.8, up 0.23 percent. All three major investor groups were net sellers. Foreign investors offloaded 486.7 billion won ($355 million) worth of shares, while institutional and retail investors sold 634 billion won and 539.7 billion won, respectively. Companies, classified separately from the three main investor groups, provided a counterweight, purchasing a net 1.62 trillion won. Much of that buying was believed to have come from share buybacks by Samsung Electronics and SK hynix. Samsung Electronics rose 0.38 percent to 261,000 won, while SK hynix gained 1.14 percent to 1.69 million won. Analysts said corporate buying could provide a short-term floor for the market but was unlikely to drive a sustained rally. “Corporate investor