(Bloomberg) -- Exxon Mobil Corp.’s credit rating was lowered one notch by S&P Global Ratins even as oil prices rebound from a historic pandemic-driven crash.

Exxon is now rated ‘AA-’ with a negative outlook, S&P said in a statement on Thursday. The rating agency warned earlier this year that oil explorers risked downgrades due to heavy levels of debt levels and the imminent transition away from fossil fuels.

Exxon posted its first annual loss in at least four decades earlier this month while outstanding debt approached $70 billion, the highest in recent memory. Even so, Chief Executive Officer Darren Woods pledged to defend the company’s dividend, the third highest in the S&P 500 Index. The driller plans to devote cash flow from higher oil prices to fund the payout and retire debt.

Brent crude futures, the international benchmark, have risen 17% this year amid rising optimism that the worst of Covid-19’s ravages are in the past and economic growth is poised to recover.

Exxon shares fell 3.1% to $49.55 at 3:32 p.m. in New York, trimming the year-to-date advance to 20%.

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