Morgan Stanley increased its use of historical cost accounting for corporate loan commitments, joining Goldman Sachs Group Inc. in moving away from the mark-to-market approach the firms had earlier used. Morgan Stanley raised the amount of loans and lending commitments that it accounted for as "held for investment," or HFI, to $9.7 billion in the fourth quarter from $800 million a year earlier. Goldman Sachs decided to make the change to some of its corporate loan book, the Wall Street Journal reported yesterday, citing people familiar with the matter. Both New York-based firms had losses on relationship lending last year and face differing treatment from regulators between HFI and fair-value commitments. Fair-value accounting often requires firms to book losses on the commitments, even if they aren't tapped by the borrowers, while commercial bank competitors avoid mark-to-market declines by holding the commitments at historical cost.