Debt collection company Credit Corp is limiting its purchase of debt ledgers, lifting its productivity and paying down debt. It may have to create more headroom to become a buyer of ledgers once more, however, short of shifting its business model into contingent collections.Credit Corp yesterday reported a lift in net profit of two per cent to $6.2 million in the half-year to December 2008. Revenue increased eight per cent to $78.5 million compared with a subdued corresponding half that triggered changes in approach at the firm.The company had used $99 million of a bank facility of $130 million as of the start of this year and said that the remaining capacity plus cash flow gave it the capacity to invest in ledger purchases of $60 million. Credit Corp invested only $13 million in new ledgers over the last half year, which enabled it to reduce bank debt by $45 million from a year before.Credit Corp sold its process service Wise McGrath to management earlier this month for $1 million and sold its Malaysian mercantile business for a small loss. Two more niche collection businesses, one servicing local government and the second in Western Australia, are also for sale.Credit Corp faces a claim from Clime Capital and litigation funder IMF over misleading market guidance in late 2007.