The combined first-quarter sales of major firms in South Korea surpassed the 700 trillion-won ($545 billion) mark for the first time on strong performances by chips, electronics, petrochemicals and auto manufacturers, a corporate tracker said Tuesday.

The total top line of 344 out of South Korea's top 500 companies by sales came to 791.5 trillion won in the January-March period, up 19.6 percent from a year earlier, according to CEO Score.

The 344 corporations cover those that have disclosed their financial statements for the first three months of the year.

By sector, the information technology, electric and electronics industry, which includes chipmaking, posted the largest sales with 143.3 trillion won.

The petrochemicals sector came next with 101.4 trillion won, followed by autos and auto parts with 78.9 trillion won, insurance with 67.2 trillion won and securities with 48.2 trillion won.

In contrast, the shipbuilding, machinery and equipment industry suffered a 2.7 percent on-year decline, and the communications sector also saw sales shrink 1.8 percent.

Global tech titan Samsung Electronics, the flagship unit of South Korea's leading family-controlled conglomerate, Samsung Group, remained the biggest company in the first quarter, with its top line reaching 77.8 trillion won.

The combined operating income of those companies came to 62.2 trillion won for the three-month period, up 5.2 percent from a year ago.

Samsung Electronics also recorded the biggest operating income with 14.1 trillion won, which was up a whopping 50.5 percent from a year earlier, according to CEO Score. (Yonhap)