The largest share of the US market the group held previously was 4.9 per cent, recorded in July 2006.
Company officials said the group's two automakers - Hyundai Motor Co and Kia Motors Corp - sold over 75,000 units in June, which accounted for 5.2 per cent of the total number of cars sold in the United States during the month. Approximately 1.46 million vehicles were sold in the US market in June.
Also last month, the group's larger automaker Hyundai broke its US monthly sales record, also previously set in July 2006.
The group's market share for the first half of the year also increased to 4.7 per cent from 4.6 per cent during the same period last year.
By Choi He-suk
The Korea Herald, Asia News Network