(Adds details on Codelco buyback plan)
By Aislinn Laing and Natalia A. Ramos Miranda
SANTIAGO, Sept 23 (Reuters) - Chile's state copper miner Codelco issued $2 billion worth of bonds on Monday, while offering to buy back short-term notes, as it seeks to smooth financing of a major overhaul of its aging mines.
The 10 and 30-year dollar-denominated bonds were issued in New York with yields of 3.02% and 3.71%, respectively, the company said in a statement.
It said it had simultaneously offered to buy back $639 million in bonds that come due in 2020, 2021, 2022 and 2023, with the goal of lightening its short-term debt load.
The move comes as Codelco seeks financing for a sprawling 10-year, $40 billion overhaul of its mines, the largest of which have been dogged by declining ore grades and increasing costs at a time when the copper price has plummeted.
Last month, Codelco sold $180 million worth of bonds and offloaded a minority stake in natural gas port terminal GNL Mejillones for $193.5 million.
The miner, which produces nearly 10% of the world's copper, returns all its profits to the state and is funded by a mix of capitalization and debt.
In April, Chairman Juan Benavides told Reuters Codelco was sufficiently capitalized after issuing $1.3 billion in 30-year bonds in January to be able to fund its mine overhaul plan.
However, Chile's economy has been hit by a fall in the copper price that makes up as much as 15% of its gross domestic product, and Codelco's operations have been further hampered by labor strife and poor weather.
The firm saw profits plunge 74% to $318 million in the first half of 2019.
The sale of the new paper was being handled by Bank of America Merrill Lynch, HSBC, JPMorgan and Scotiabank, IFR reported. (Reporting by Aislinn Laing; writing by Dave Sherwood; editing by David Gregorio and Rosalba O'Brien)