TOKYO -- Japanese companies issued 51.3% of bonds in denominations other than yen during the first half of the year, a record-high proportion, as businesses increasingly looked beyond the border to raise funds.

The issuances in the period totaled $40.9 billion, data from Dealogic shows, with nonfinancial companies accounting for $19.9 billion.

Nonfinancial companies have been turning to foreign-currency-denominated bonds to directly procure operating capital for offshore operations. Financial institutions are facing tougher regulations, meanwhile, and tapping diverse rosters of investors in foreign markets for funds.

Outside of the dominant dollar and the euro, Mizuho Bank and MUFG Bank made headlines in January when they became the first Japanese businesses to issue yuan-denominated "panda" bonds on the mainland. Also this year, Toyota Motor floated bonds denominated in such currencies as the Thai baht and the Malaysian ringgit through Asian subsidiaries.

Japanese companies have long relied on foreign-denominated bonds as a means to ward off the negative effects of a strong yen. But down the road, a weak yen could bring about a heavy repayment load.

Corporate bonds issued in Japan carry low yields amid historically low interest rates. But a growing number of companies with high credit ratings find it relatively favorable to issue non-yen debt when the costs of foreign currencies are taken into consideration.

"As a means for companies to reliably procure operating capital, issues of foreign-currency-denominated corporate bonds will continue growing," said Yosuke Todaka of Mizuho Securities.