(New throughout, adds results of sale)
By Richard Lough and Eliana Raszewski
BUENOS AIRES, Feb 4 (Reuters) - Argentina's state-run energy company YPF sold $500 million of bonds on Wednesday, a third less than it had offered in its first international debt sale since the South American country tipped into default in July.
YPF's 2018 and 2024 notes fetched yields of 8.5 percent and 8.95 percent respectively. Local traders said YPF received offers for up to $1 billion in debt, but many were for higher yields than it would accept.
"Although the demand was higher than the maximum we were authorized to issue, we decided to take the amount that best combined financial cost and placement, consistent with our serious financing strategy," YPF Chief Financial Officer Daniel Gonzalez said in a statement.
Argentina needs to ramp up production from its vast but barely tapped Vaca Muerta shale oil and gas resource in order to reverse a gaping energy sector trade deficit that is pressuring low foreign reserves.
Before the sale, Cabinet Chief Jorge Capitanich said during his daily news conference the $750 million bond offering "was aimed at boosting investment volumes in the context of becoming energy independent.".
Citigroup Inc, JPMorgan Chase & Co and Banco Itau Argentina were acting as lead mandate banks in the sale, and the securities are listed in Luxembourg and Buenos Aires, Thomson Reuters' IFR reported.
Argentina has the world's second largest shale gas resources and fourth largest shale oil resources but officials say financing is beyond the reach of state-controlled energy firm YPF and regional governments.
Chevron Corp, Petronas, Royal Dutch Shell and Total SA have dipped their toes in but their initial investments fall short of putting Argentina on the path to energy independence. Chinese energy giant Sinopec signed a preliminary agreement on Jan. 28 to develop projects in Vaca Muerta.
Last year, the Argentina's oil and natural gas imports exceeded its energy sector exports by more than $6 billion.
On Wednesday, a government stimulus programme to increase production and bolster exports kicked in, with producers set to receive a maximum $3 per barrel subsidy when quarterly output exceeds a government-set base level.
Exporters will receive up to an additional $2 for every barrel of crude oil shipped abroad.
The stimulus package was part of a mid-January deal between the federal government, oil-producing regions and energy companies in a government-led drive to keep oil production steady while global oil prices hit six-year lows. (Additional reporting by Jorge Otaola, Maximiliano Rizzi and Sarah Marsh in Buenos Aires; Editing by W Simon and David Gregorio)