It had reported net loss of Rs 114.70 crore during the same quarter of last fiscal, 2013-14, Tata Power said in a statement.
The net loss during the first quarter of 2014-15 has narrowed "mainly due to lower forex losses and depreciation in CGPL (Coastal Gujarat Power Limited (CGPL)".
The 4,000 MW Mundra ultra mega power project is being implemented by CGPL, a wholly-owned subsidiary of Tata Power.
The company's revenue has dropped to Rs 8,765.65 crore for the first quarter ended June 30, 2014 from Rs 9,339.40 crore for the same period last fiscal "mainly due to lower realisation by coal companies, lower fuel cost in Mumbai operations and lower volume traded by Tata Power Trading Company Ltd.