People walking by a sign for Freddie Mac headquarters in McLean, Virginia, US. Troubled US mortgage firm Freddie Mac yesterday reported a second quarter net loss of $6 billion and sought another $1.8 billion from the Treasury to contain the red ink. The government-backed company said its strategies to boost business and “sustainable homeownership” were taking hold but cited high unemployment posing “very real challenges” for the already embattled housing market.