BOGOTA, Feb 8 (Reuters) - Private-sector investment in oil and gas exploration in Colombia is forecast to decline by around a third this year, the Colombian Petroleum Association (ACP) said on Wednesday.

The forecasted decline in private-sector investment in exploration follows a sharp hike in funding for exploratory activities in 2022, as well as the introduction of a new tax reform that will levy duties of up to 15% on crude oil when prices go above a certain level.

Colombia's leftist President Gustavo Petro has set his sights on weaning the Andean country from its dependency on oil exports, blocking new auctions for oil and gas blocks.

Exploration investments, including from state-owned Ecopetrol, more than doubled in 2022 versus the previous year to $1.29 billion, the ACP said, citing soaring oil prices and a better regulatory environment.

Total exploration investment is forecast to fall just 4% in 2023 to $1.24 billion because Ecopetrol, Colombia's largest producer, is increasing its investments, the ACP told journalists.

However, the private sector is expected to cut its own exploration investments to between $650 million and $700 million this year - a 33% cut versus 2022 - partly due to a less favorable fiscal environment, the ACP said.

"That is a very high percentage," ACP President Francisco Lloreda said, adding that he hopes studies led by the finance ministry will push the government to adopt a slower transition that takes fiscal and productivity changes into consideration.

"This is going to take much longer than perhaps the current government would like," Lloreda said.

Total exploration and production hit $4.88 billion last year, up from $3.09 billion in 2021, the ACP said, adding that the figure could rise to $5.05 billion this year, driven by a 6% rise in production-sector investments.

Average daily oil output in Colombia is expected to rise 2.1% to 770,000 barrels per day this year, the ACP added. (Reporting by Oliver Griffin; Editing by Paul Simao)