TORONTO, April 24, 2013 /PRNewswire/ – Sierra Metals Inc. (TSX-V:SMT) (BVL:SMT) (“Sierra Metals” or the “Company” previously Dia Bras Exploration) is pleased to provide this revised news release which includes additional supporting details on the pre-feasibility study completed by Gustavson Associates, LLC (“Gustavson”) of Lakewood, Colorado, for its Bolivar copper-zinc-silver mine located in Chihuahua State, Mexico announced on April 17, 2013.  The study, mine plan and reserve estimate are based on Gustavson’s work and mine plan.

Sierra Metals has conducted exploration, development and mining at the Bolívar Mine since 2003.  Exploration includes geologic mapping and diamond core drilling in the El Gallo, Increíble and Alta Ley areas, which are located within the area of resource modeling, and in the La Narizona, La Montura, La Pequeña and El Val areas, which are located outside the area of resource modeling.  Pilot mining has been conducted and has provided valuable information regarding metallurgy, recovery rates, smelter treatment and refining charges, etc.

Bolivar built its new Piedras Verdes ore processing mill in 2010-2011 and declared commercial production in November 2011 with a processing capacity of 1,000 tonnes per day.  The data of prior production were used in the development of the pre-feasibility study preparation and as a guide to continued mining as well as doubling of production capacity to 2,000 tons per day, which will be effective by the end of April 2013.

This work resulted in a NI 43-101 and CIM compliant resource estimate (see press release of August 30, 2012), which is the basis for this pre-feasibility study.  Table 1 shows the Measured and Indicated Resources of each deposit with the compliant resource estimate broken out by Measured, Indicated and Measured+Indicated. Table 1A shows the Resources by each deposit.

The effective date of this resource estimate is April 5, 2013, and was completed by Gustavson as an independent report by Zachery J. Black, Qualified Person as defined by NI 43-101.  Mineral resources are not mineral reserves and do not demonstrate economic viability. There is no certainty that all or any part of the mineral resource will be converted to mineral reserves.

About Sierra Metals

Sierra Metals Inc. is a Canadian mining company focused on precious and base metals from its Yauricocha mine in Peru and its Bolivar mine in Mexico. The Company is also advancing its Cusi silver project in Mexico from advanced development into commercial production. In addition, Sierra Metals is exploring several precious and base metal targets in Peru and Mexico. Projects in Peru include Adrico (gold), Victoria (copper-silver) and Ipillo (polymetallic) at the Yauricocha Property in the province of Yauyos. Projects in Mexico include Bacerac (silver) in the state of Sonora, La Verde (gold) at the Batopilas Property in the state of Chihuahua, and Las Coloradas (silver) at the Melchor Ocampo Property in the state of Zacatecas.

The Company’s shares trade on the Bolsa de Valores de Lima and TSXV under the symbol “SMT”.

SOURCE Sierra Metals Inc.