Colombian electricity generator ISA (ISA.CN) issued $330 million in international bonds, the company said on Thursday, and will use the funds to substitute debt. The 12-year paper has a yield of 3.825% and the issue was more than four times oversubscribed. "The resources will be used for an internal and external debt substitution operation," said the company, which has interests in electricity, roads and telecoms in Colombia, Brazil, Chile, Peru, Bolivia, Argentina and Central America through 51 partners and subsidiaries. The issue was listed on the Singapore stock exchange and drew participation from investors in the United States, Canada, Europe, Asia and Latin America, the company said in a statement. Colombian state oil company Ecopetrol in August said it would acquire 51.4% of circulating ISA shares for $3.58 billion, part of Ecopetrol"s strategy to diversify its energy interests.