South Korea's top 10 largest companies lag behind their global rivals in their spending for research and development projects, data showed Wednesday.

In terms of a ratio of research and development spending to revenue, the average spending by the nation's top 10 firms is about 76 percent that of their global rivals, according to the data by market tracker CEO Score.

Of the 10 firms, Samsung Electronics Co. and SK Innovation Co. matched their global rivals in research and development spending, the data showed.

Samsung Electronics Co. spent $10 billion on research and development during the first nine months of this year, with sales standing at $134.5 billion.

Samsung invested 7.5 percent of its revenue into research and development, compared with 4.4 percent by Apple Inc.

SK Innovation spent 0.4 percent of its revenue on research and development, compared with 0.3 percent by China Petroleum & Chemical Corp.

Besides Samsung Electronics and SK Innovation, other firms lag far behind their global rivals.

POSCO invested a 0.9 percent of its revenue into research and development, compared with 1.4 percent by Japan's Nippon Steel & Sumitomo Metal Corp., according to the data.

Hyundai Motor Co. spent 2.2 percent of its revenue on research and development, compared with 4.1 percent by Toyota Motor Corp.

CJ Cheiljedang Corp., South Korea's largest food company, invested one percent of its revenue into research and development, compared with 1.9 percent by Nestle SA, according to the data.  (Yonhap)