BOGOTA (Reuters) - Colombia's majority state-owned energy company Ecopetrol said on Friday that it is in talks with U.S. oil major Occidental Petroleum to possibly buy a stake in CrownRock.

Ecopetrol, in a statement, did not include additional details and added that a final decision on the size of the stake and the amount it could pay were subject to analysis.

Occidental moved to buy shale oil producer CrownRock in December in a $12 billion cash-and-stock deal, which included debt.

In May, Occidental reaffirmed its plans to sell $4.5 billion to $6 billion of assets within 18 months of closing the CrownRock purchase, which it said could be completed by August.

Shale oil production does not currently take place in Colombia but Ecopetrol, the country's largest company, has shale operations in the U.S. Permian basin.