(Reuters) - S&P Global Ratings revised on Wednesday the outlook for Mexico's state-oil firm Pemex to stable from negative, after it reviewed Mexico's long-term outlook.

According to the rating agency, high crude oil prices are improving Pemex's credit metrics, although the company's weak liquidity continues to affect its assessment of its stand-alone credit profile.

"The stable outlook on Pemex's global scale rating reflects that of the sovereign and our view that the close relationship between the company and the country will remain unchanged in the coming years," it said in a statement.

(Reporting by Carolina Pulice and Adriana Barrera; editing by Christian Schmollinger)