Market risk exposures of balance sheet asset values are becoming an increasingly important accounting issue. in oil and gas, oilfield exposures to oil prices are specific and contractual, presenting a contingency problem for investors, financial analysts, standard setting bodies and government agencies. Our paper uses an extensive sample of 292 oilfields to provide evidence that the US Securities and Exchange Commission (SEC) supplementary disclosures do not capture the price sensitivities of oil and gas disclosures implicit in the two main forms of oilfield ownership, concession and production sharing contracts (PSCs). Current asset disclosures neither distinguish between global variations in oilfield ownership terms, nor on market risk implications for the value of oilfield assets. Importantly, we show that unlike concessions, reserve and production disclosures vary in response to oil price movements for PSC regimes. Our results highlight the need to differentiate PSC disclosures from concession fields, and to fully reflect price risks implicit in oilfield ownership contracts. We extend findings by Rajgopal [1999. Early evidence on the informativeness of the SEC's market risk disclosures: the case of commodity price risk exposure of oil and gas producers. The Accounting Review 74, 251-280] and propose refinements to capture market risk in financial reporting. (C) 2007 Elsevier Ltd. All rights reserved.