The following companies had unusual price changes in Bogota trading. Stock symbols are in parentheses and prices are as of 4 p.m. local time.

The IGBC Index dropped 1.5 percent to 13,079.57, while the Colcap Index dropped 1.5 percent to 1,585.81.

Ecopetrol SA (ECOPETL CB), Colombia’s biggest oil company, dropped 4.2 percent, the most since Sept. 22, to 4,320 pesos.

Colombia seeks to raise as much as $3 billion this year from the sale of a stake in Ecopetrol by tapping sovereign wealth funds and international investors, Mines and Energy Minister Mauricio Cardenas said today.

The government will sell as much as 3 percentage points of its stake in Ecopetrol, pending congressional approval that is probable in the first half of the year, Cardenas said in an interview in Bogota today. The government now owns about 88.5 percent of the company.

Empresa de Telecomunicaciones de Bogota SA (ETB CB), the city-run phone company serving Colombia’s capital, rose 10 percent to 534 pesos.

Mario Contreras, who took over as the company’s president in September, presented his resignation effective Jan. 16, according to a regulatory filing today. The filing gave no further details.

The Bogota mayor’s office plans to merge ETB, as the company is known, with other public companies and will not sell its majority stake in the company, Eduardo Noriega, the city’s secretary general, said yesterday in a statement prepared by Mayor Gustavo Petro, according to a statement on Petro’s website.