ADDIS ABABA, Oct 1 (Reuters) - Germany's Commerzbank <CBKG.DE> announced plans on Monday to open a branch in Ethiopia's capital Addis Ababa.

The move comes before a one-day visit by German Chancellor Angela Merkel to the Horn of Africa nation this week.

"Commerzbank considers Africa as a rapidly emerging economic opportunity and plans to enhance its links with the African market," the Frankfurt-based bank said in a statement.

Germany is the biggest buyer of Ethiopian coffee, one of the country's key foreign exchange earners.

It bought 36,399 tonnes of coffee worth $86 million in 2005/06 compared with 50,115 tonnes valued at $117.6 million in 2006/07, according to the Ministry of Trade and Industry.

During her visit to Ethiopia, Merkel is expected to meet Prime Minister Meles Zenawi and address the 53-member African Union, which is headquartered in Addis Ababa.

Officials said she would also visit South Africa and Liberia.