Fresnillo, the world's largest primary silver producer, said the board has approved the pre-feasibility study for the development of the first stage of Saucito project in Mexico.The Saucito project is located eight kilometres southwest of the Fresnillo mine and aims to be another world class silver mine.The pre-feasibility study considers a 3,000 tonnes per day operation starting in 2011. The expected annual production at full capacity will be approximately 9m ounces of silver and 45,000 ounces of goldThe estimated initial investment will be $309m with a sustaining capital of $68m over the life of the mine."This is a very exciting chapter in our growth strategy as the discovery and development of Saucito illustrates our main drivers of value creation: large, long life assets developed by consolidating districts," said chief executive Jaime Lomelin.