Receivables manager Collection House increased its earnings by 26.6 per cent in the December half, despite having some teething trouble with its new commission collection business. Net profit rose from A$5.1 million in the six months to December 2011 to $8.1 million in the latest half.Return on equity rose from 11.9 per cent to 12.6 per cent.Revenue growth of eight per cent came from the purchased debt ledger division.Last year, the company established a commission collections business and yesterday it reported that there was no revenue growth in this segment.Collection House's chief executive, Matt Thomas, said: "During the first half of the year a number of unprofitable or low margin contracts were voluntarily terminated, and new, more profitable contracts were secured to replace that revenue."On the purchased debt ledger side, the company acquired $33.9 million of impaired loans. PDL acquisition in the previous corresponding period was $30.5 million.Thomas said: "Substantial purchases during the half will support higher collections in the June half."Thomas said he expected PDL investment to fall in the June half.The company increased its interim dividend by 13 per cent to 3.6 cents a share and announced that a dividend reinvestment plan would be available with a five per cent dividend.