(Adds details on consumption, one-off gains)
LISBON, July 31 (Reuters) - Portugal's largest utility, EDP Energias de Portugal, on Thursday posted an unexpected 12 percent rise in first-half net profit due to one-off gains from asset sales in Brazil and the renegotiation of labour contracts in Portugal.
The utility said net profit totalled 673 million euros (US$901 million), compared with an average forecast in a Reuters poll of analysts of 517 million euros .
Earnings before interest, tax, depreciation and amortization (EBITDA) rose 1 percent to 2 billion euros, exceeding the market consensus of 1.86 billion euros, even though the combined consumption of electricity generated by EDP in its main markets in Portugal and Spain declined by almost 1 percent.
EDP said it had an extraordinary gain of 129 million euros from new labour contracts at home, another 129 million from the sale of a 50 percent stake in a Brazilian power project and 56 million from the sale of natural gas transport assets in Spain.
The rise in profit also came despite an extraordinary tax on energy companies imposed by the government to meet Portugal's budget deficit goals.
EDP said there was a slight recovery of demand for energy in Portugal, which last year started to emerge from its deepest recession since the 1970s and is expected to post its first full year of growth this year.
$1 = 0.7472 Euros Reporting By Andrei Khalip; Editing by Keiron Henderson, Toni Reinhold