SINGAPORE - A third-party assurance review on Noble Group's valuation contracts and models has found that the group's accounting practices comply with relevant standards.

PricewaterhouseCoopers (PwC) said on Monday that the commodities trader adhered to international requirements and standard industry practices when valuing contracts.

"Indeed, in some aspects of the model construction (such as the development of discount rates and development of counterparty credit risk curves), Noble has an approach which is more sophisticated than that of many non-financial companies," noted the accounting firm.

But PwC, in the report commissioned by the group, also recommended that Noble Group do more to strengthen the role of compliance or internal audit in order to improve its valuation of some commodity contracts.

Noble's investment grade credit rating is at stake after the company was first accused of poor accounting practices by shortseller Iceberg Research in February. The embattled firm has refuted the claims, while hiring PwC to review its accounting methods.

Noble Group said in a statement that it will begin implementing PwC's recommendations immediately to ensure the company "remains a leader in its industry" with regard to mark-to-market valuations.

Mr Richard Elman, chairman of the board at Noble Group, said: "I am delighted that we have received a strong validation of our processes and controls and shareholders can now be assured, as we have always known, that our balance sheet fairly reflects the value of our long term contracts.

"We continue to focus on building our business in markets that offer us tremendous opportunities."

With sales of US$86 billion last year, Hong Kong-headquartered Noble is one of Asia's largest firms to find itself in a reputational battle over accounts where consequences can be long-lasting.