Colombia's state oil company Ecopetrol offered 20 oil and gas blocks for auction on Thursday, part of a company plan to cut back amid low global crude prices.
One-hundred and thirty-eight companies from 21 countries, some of which already operate in the Andean country, attended the auction launch,
Ecopetrol said in a statement.
"The fields are close to logistical facilities, which adds extra attraction for small and medium sized
gas and oil companies," the company said.
The blocks will be sold in an electronic auction on Sept. 30.
Ecopetrol has been selling assets in a bid to fund its investment plan, which is down by $1.8 billion this year.
(Reporting by Nelson Bocanegra; Writing by Julia Symmes Cobb; Editing by Bernard Orr)