April 29 (Reuters) - The Iowa unit of U.S. power company Alliant Energy Corp said Monday it reached an agreement with the state's consumer advocate that would allow the utility to build a 600-megawatt (MW) natural gas-fired power plant, if allowed by regulators.
Interstate Power and Light, Alliant's Iowa utility unit, said it hopes to have a decision from Iowa's utility regulators by the fourth quarter of 2013.
If approved by the Iowa Utilities Board, the state utility regulator, Alliant said the new Marshalltown power plant could enter service by the spring of 2017.
In addition to the proposed Marshalltown plant, Alliant said it was also making investments to reduce emissions and increase the efficiency of its coal plants and retiring some older, less efficient coal plants.
The company also said it is working on the execution of new long term power purchase agreement for 431 MW from NextEra Energy Inc's Duane Arnold nuclear reactor in Iowa.