Debt collector Collection House has produced a big increase in net profit for the year to June, on the back of a record investment in distressed debt portfolios and a reduction in its gearing.The company reported a net profit of A$18.7 million for the year - an increase of 20 per cent over the previous corresponding period. Revenue rose ten per cent to $107.3 million.Return on equity was 13 per cent, unchanged from the previous year.It purchased $82.2 million of debt portfolios - an increase of 50 per cent and a record for the company. It was able to do this while reducing its gearing ratio from 41 per cent to 39 per cent.During the year the company replaced a number of systems, including its core collection software platform. Collection House chief executive Matthew Thomas said in a statement that investment in systems gave the company a competitive advantage.