South Korea\'s listed companies are likely to register less operating profit than estimated earlier this year amid signs of a global economic slowdown, a report showed Sunday. According to the report by FnGuide Inc., a financial information provider, 129 major listed companies are expected to chalk up a combined operating profit of 92.8 trillion won (US$85.4 billion) for all of this year. The estimate is based on analysts\' earnings forecasts for the listed companies, which close their books in December. It was down from a 93.3 trillion won prediction made early this month and 94.3 trillion won projected in February. \"Earnings forecasts for both U.S. and South Korean companies have begun to face downward adjustments since June due to lowered expectations for the global economy,\" said Lee Jae-man, an analyst at Tong Yang Securities Co. According to FnGuide, the technology sector has suffered the biggest downward adjustment, which could have a negative impact on the local bourse due to their high market capitalization. Eighteen listed companies that were surveyed are projected to post a combined operating profit of 18.5 trillion won this year, far lower than an estimate of more than 20 trillion won made early this year. In particular, the market forecast for top-cap tech giant Samsung Electronics Co.\'s operating profit for the second quarter has been lowered to 3.9 trillion won from 4.2 trillion won estimated at the start of the year, it said. \"Most analysts have retained their target price for Samsung, but the downgrade in its earnings forecast reflects worsening economic conditions in advanced countries,\" said Shin Il-pyeong, a senior researcher at Daewoo Securities Co. Market watchers said the downgrade in earnings forecasts for listed companies is feared to increase the volatility of the local stock market, which has been losing momentum in the wake of the Greek debt crisis. On Friday, the benchmark Korea Composite Stock Price Index (KOSPI) dropped 0.72 percent to 2,031.93, the lowest close since March 23, as tech companies took a dive on grim second-quarter earnings forecasts.