Japanese online retailer Rakuten Inc said it would raise $1.5 billion through new share issuance to repay debt, and its stock slid 6 percent on the planned dilution.

The highly acquisitive company, which bought messaging service provider Viber Media and U.S. rebate site operator Ebates last year, said it wanted to improve the flexibility of its financial strategy.

In the biggest secondary offering by a Japanese company so far this year, it will issue about 100 million new shares, boosting the number of its shares by 7.5 percent.

The shares will be offered in both Japan and overseas and the price will be determined between June 23 and June 26, it said.

Rakuten said 90 percent of the proceeds would go towards repaying debt and the rest would be used in investments, including bolstering its network infrastructure and developing or acquiring new software for its e-commerce site.

$1 = 124.3300 yen