The South Korean advertisement industry is forecast to experience a slump despite the upcoming Rio de Janeiro Summer Olympics, mainly due to the sluggish economy and a time difference between the two countries, industry sources said Tuesday.

Sporting events, such as the Olympics and the World Cup, have typically boosted the advertisement industry, they said.

Marketing companies launched various TV ads and promotions designed to enhance awareness of the games and help companies sell more products just ahead of the London Olympics four years ago, the source said.

This year, however, major companies have not yet launched ad campaigns that deal with the Olympics, except for a few, such as McDonald's and Korean Air Lines Co., which officially sponsor the games.

"One of the main reasons is that there is a 12-hour time difference with Rio de Janeiro," said an industry source, noting that another reason is that major South Korean companies and potential advertisers have been struggling with the slumping economy.

The state-run ad agency Korea Broadcast Advertising Corp. said that the revenues from ad spending in August are forecast to be similar to that of July.

The sources said that the sales of TV ad slots during the Olympic period have fallen short of KOBACO's expectations.

However, the revenues from the ad industry will log better-than-expected sales if South Korean athletes perform well in the games, KOBACO said.

Industry sources said many commercials focusing on the Olympics tout athletes with tough backgrounds who are expected to contend for medals.

Son Yeon-jae, who came in fifth in the London Games for the first time as a South Korean Rhythmic gymnast, was picked by advertisement agencies as the "most favored athlete."

Swimmer Park Tae-hwan also featured in numerous advertisements both for TV and online, promoting laptops, smartphones and other products, during the previous Olympics. (Yonhap)