BRASILIA, May 15 (Reuters) - The corporate investment wing of Brazil's national development bank reported a first quarter loss of 891 million reais ($297.3 million) due to falling share prices, the bank, known as BNDES, said on Friday.
A year ago, the holding company, BNDES Participações SA , posted a profit of 181 million reais.
The portfolio of BNDESPAR, as the BNDES unit is known, includes shares and convertible debt of some of Brazil's largest companies, such as state-run oil company Petroleo Brasileiro SA and iron ore miner Vale SA.
Petrobras shares have been hit by low oil prices and a massive corruption scandal while Vale has been battered by declining world prices for iron ore.
BNDES said in a statement that BNDESPAR has written off 1.09 billion reais in losses, 70 percent of which was due to investment in Vale preferential shares.
Despite the share price drop, BNDESPAR stands to gain 2 billion reais in realized gain on Vale stock, it said.
$1 = 3.00 Brazilian reais Reporting by Anthony Boadle; Editing by Ken Wills