A remake of Japanese film Enka No Hanamichi, the film tells the story of a wanna-be rocker who ends up singing Trot (Korean country-style music) behind a mask and becoming a star.
Launched into pan-Asian popularity after his role in My Sassy Girl, Cha Tae-Hyun stars as the hapless singer.
The film took in 1.7 million admissions last February and has remained as one of the top ten Korean films of the year.
Avex, best known for its music and management businesses, has recently moved into the film industry, and is an investor in John Woo's Red Cliff.
Highway Star is the company's first Korean film acquisition, although it is handling video rights to top pan-Asian star Bae Yong-Joon's epic TV series Taewangsashingi.
The film was pre-sold to Thailand, Malaysia and Brunei. Thailand will be the first foreign country to open the film on August 2.
The sale comes after a year of dramatically dropping export numbers to Japan.