An auction for a fresh batch of 10-year Japanese government bonds drew strong demand Thursday, with investors filing the most bids on record amid growing jitters over a slowdown in the U.S. and Japanese economies.

Bids for the September issue totaled an all-time high of 104.45 trillion yen, up from 13.89 trillion yen for the August issue, the Finance Ministry said, signaling that investors have began shifting funds to safe-haven assets.

The ministry auctioned about 1.59 trillion yen worth of the No. 263 government bond issue, driving the bid-to-cover ratio -- gauging the amount of bids to the amount auctioned -- to 65.75, also a record high.

The ratio was up sharply from 8.7 in the previous auction for 10-year government bonds, held on Aug. 3.

The ministry set the coupon at 1.6 percent per year for the September issue. It was down from 1.9 percent per year for the August issue, the highest in three years and 10 months.

The settlement date for the latest issue is Sept. 21. The bonds mature on Sept. 20, 2014.