Primus Guaranty Ltd’s profits edged down slightly to $84.7 million in the first quarter of 2011 from $86.5 million the previous year.The net income for the first quarter was driven by a net unrealised mark-to-market gain of $82.7 million on Primus Financial Products LLC’s consolidated credit swap portfolio.The company’s economic results (non-GAAP financial measures) for the first quarter 2011 were $8.7 million or 23 cents per share compared with an economic results loss of $40.9 million or $1.01 per share for the same period in 2010.The economic results for the first quarter resulted from a premium revenue of $11.2 million, gains on retirement of debt of $2.8 million, offset by net operating costs of $4.3 million.