(Corrects paragraph 5 to show Sempra unit considering construction of windfarm in Mexico)

MEXICO CITY, Feb 3 (Reuters) - The city of Los Angeles, which has a goal of getting 20 percent of its power from renewable sources, agreed in principal on Tuesday to purchase Mexican geothermal power, Mexico's state-owned power monopoly said.

Under the proposed agreement Mexico's Federal Electricity Commission (CFE) would sell the city-owned Los Angeles Department of Water and Power approximately 100 MW of power from its 720 MW Cerro Prieto geothermal generating station.

Final terms of the agreement are still being concluded.

Other California utilities have explored sourcing renewable power from Mexico as they strive to meet the state's 20 percent renewable power standard. The standard takes effect in 2010.

A unit of Sempra Energy (SRE.N: Quote, Profile, Research) has proposed to construct a wind power project in northern Baja California that would generate between 150 and 175 MW of power. Construction of this project is expected to begin in 2010.

The Los Angeles Department of Water and Power serves 1.4 million customers and is the biggest municipal utility in the United States.

Fossil fuels currently generate 76 percent of the power sold by the LADWP. (Reporting by Robert Campbell)