UPDATE 1-Colombia says Glencore sells assets at $549 mln

(Adds details on deal and earlier bond proposal)

BOGOTA, March 3 (Reuters) - Swiss-based commodities firm Glencore has agreed to sell its assets in a Cartagena refinery deal to Colombian state oil firm Ecopetrol for $549 million, the Colombian company said on Tuesday.

Glencore held 51 percent of the Reficar operation and Ecopetrol the remaining 49 percent stake. Glencore had decided to sell its part because of difficulties getting financing for the refinery upgrade due to the world financial crisis.

"Ecopetrol ratified its commitment to developing the expansion project and modernization of the Cartagena refinery, the company said in a statement.

Earlier on Tuesday, Ecopetrol also said it would propose an issue of up to $8.1 billion in nonconvertible bonds to finance investments through 2011. If approved by shareholders, the paper will be placed in Colombia or on international markets.

Ecopetrol wants to boost output at the refinery in the port city from 75,000 barrels per day to 140,000 bpd as a central part of the Andean country's plans to become self-sufficient in gasoline and expand its petrochemicals industry.

Government officials estimate the project will cost around $3 billion and have suggested they will seek another partner in the deal. Brazil's Petrobras (PETR4.SA)(PBR.N) and General Electric Co. (GE.N) are interested in participating.

Foreign investment in Colombia's energy and mining sectors has flourished since President Alvaro Uribe came to office in 2002 and sent troops to drive back the country's leftist guerrillas and take control of areas battered by violence.

Oil production is expected to rise this year to around 650,000 bpd compared with 587,000 bpd in 2008. Colombia produced 820,000 bpd in the 1990s, but production was crimped by guerrilla violence and attacks on pipelines.

Glencore's decision to abandon the project is the latest sign the global economic slowdown is hurting its operations. It had already halted projects and fired hundreds of mine workers in Peru and Bolivia. (Reporting by Patrick Markey in Bogota; Editing by Christian Wiessner)