Revenue fell 30 per cent to £357 million in the three months to December 31st.
The company reported a profit of $15.5 million for the period in the previous year.
The 600 job losses will come in fiscal 2010, and will make up 24 per cent of the firm’s global workforce.
THQ also reported that it expected its Q4 would be ‘significantly’ worse than previously expected – and that planned to cut spending by $220m in FY 2010.
"Unquestionably this is a challenging time for THQ," Chief Executive Brian Farrell said. "The video game sector as a whole grew in 2008, and clearly, we did not participate fully in that growth."
The firm announced that it would cut 250 jobs when it announced its Q2 results in November last year.