The Treasury issued a broad authorization allowing Petróleos de Venezuela S.A., or PDVSA, to directly sell Venezuelan oil to U.S. companies and on global markets, a massive shift after Washington for years had largely blocked dealings with Venezuela’s government and its oil sector.

Aimee Picchi is the associate managing editor for CBS MoneyWatch, where she covers business and personal finance. She previously worked at Bloomberg News and has written for national news outlets including USA Today and Consumer Reports. Although the Trump ...