U.S. firm Sempra Energy has been awarded a contract to build and operate a $569 million gas pipeline in the northwestern Mexican state of Sonora, the CFE state electricity monopoly said.

The Sasabe-Guaymas project was awarded to Sempra after it offered "a flat rate of $0.13 per million BTU (British Thermal Units)" transported, the CFE said in a statement.

That offer was the most "suitable" for the CFE and "fulfilled all the auction requirements," it said, adding that four other companies also were in the running.

The pipeline, which will stretch for 530 kilometers (330 miles) and have a minimum diameter of 36 inches, will guarantee supplies for the CFE's current and future thermoelectric plants in northwestern Mexico, as well as the region's productive sectors, the CFE said.

The contract covers the hiring of natural gas transport services for 25 years and involves the delivery of the fuel from Sasabe, on the U.S.-Mexico border, to the Puerto Libertad and Guaymas II thermoelectric plants and two future plants the CFE plans to build at the Guaymas complex.

The first stage of the gas pipeline from Sasabe to Puerto Libertad is to be completed in October 2014, while the second stage from Puerto Libertad to Guaymas - in the southwestern part of Sonora state - is to be finished in July 2015, the CFE said. EFE