The Calgary-based company said its most recent quarterly loss amounted to $1.251 million, or two cents per share, compared to $1.246 million, or two cents per share, in the second quarter of 2011.
Natural gas sales totalled $212,000, up slightly from $207,000 in the year-ago quarter.
The company bought a private Brazilian oil and gas company, Alvorada Petroleo SA, for US$37 million in March.
Until last year, Fortress had focused on Canadian natural gas exploration, development and production but sold most of its assets in the third quarter of 2010.
It later was subject to a tax challenge by the Canada Revenue Agency, which demanded a $9-million preliminary payment that drained Fortress's coffers and forced it to seek protection under the Companies' Creditors Arrangement Act.
In October, the CRA withdrew the claim after reviewing the case and Fortress emerged from CCAA protection.