Kevin McCoy

USA TODAY

New York's top law enforcement official is investigating why U.S. energy giant ExxonMobil (XOM) has not written down the value of some of the company's assets despite the continuing global slump of oil prices.

New York Attorney General Eric Schneiderman is examining the issue as his office continues a broader accounting investigation into whether ExxonMobil misled investors about the impact of climate change on the company, a person familiar with the matter said Friday.

ExxonMobil investigated over climate change statements

The person spoke on condition of anonymity because specifics of the accounting review have not been publicly disclosed.

The Irving, Texas-based company issued a formal statement saying its financial results "are in accordance with the accounting and reporting standards of the Securities and Exchange Commission and the Financial Accounting Standards Board."

U.S. oil producers wrote down $177 billion in assets last year, and an additional $15 billion in the first quarter of 2016, according to estimates this year by IHS Energy. Since the slide in oil prices started in 2014, many producers have publicly acknowledged that the value of their oil field assets no longer meet previous economic projections, resulting in announcements of lower earnings.

Acknowledging the company has not taken such write downs, ExxonMobil said Friday "we do not have any material impairment impacts in our financial results."

In its 2016 annual report, ExxonMobil said it conducted an assessment of its major assets most at risk for potential impairments and write downs late last year. "The results of this assessment indicated that the future undiscounted cash flows associated with these assets substantially exceed the carrying value of the assets," the company said Friday.

ExxonMobil wins bidding war for InterOil for $2.5 billion

In the broader investigation, Schneiderman's office in November subpoenaed ExxonMobil for financial records, statements and other climate-change-related material dating back to 1977, USA TODAY and other news agencies reported.

The probe focuses on whether the company issued timely and accurate disclosures about how its climate-change research, the impact of long-term environmental shifts and any movement away from usage of fossil fuels could have on the company's bottom line.

"ExxonMobil has included information about the business risk of climate change for many years in our 10-K, Corporate Citizenship Report and in other reports to shareholders," the company said in November.

ExxonMobil shares fell $1.05 Friday to close at $84.03.

Follow USA TODAY reporter Kevin McCoy on Twitter: @kmccoynyc