The issuance of asset-backed securities (ABS) in South Korea sank 39.2 percent in the first quarter of this year from a year earlier as the state-run mortgage loan agency saw a drop in its financial instrument sale, the financial watchdog said Thursday. A combined 8.1 trillion won (US$7.8 billion) worth of ABSs were issued in the January-March period, compared with 13.4 trillion won a year earlier, according to the Financial Supervisory Service (FSS).