WASHINGTON — The White House has pressured the chief executives of some of America’s largest energy, financial and industrial corporations into canceling plans to attend an international economic forum in Russia to be hosted by President Vladimir V. Putin this month, the latest effort to isolate Moscow in retaliation for its intervention in Ukraine.

The top executives of such giants as Alcoa, Goldman Sachs, PepsiCo, Morgan Stanley, ConocoPhillips and other multinational companies with business in Russia have either pulled out of the conference or plan to do so after an intensive lobbying campaign by President Obama’s advisers. Corporate officials predicted that nearly every American C.E.O. will now skip the forum in St. Petersburg.

The personal telephone calls from White House officials and cabinet secretaries have put the executives in an awkward position because they do not want to run afoul of the Obama administration, but they are acutely aware that Mr. Putin takes attendance at this event, which has become an important showcase for him on the world stage. Hoping to avoid alienating Mr. Putin at the risk of jeopardizing their operations and tens of thousands of employees in Russia, several companies are sending lower-level executives based in Moscow or Europe to the meeting from May 22 to 24.

The St. Petersburg forum, styled as Russia’s answer to the annual economic meeting in Davos, Switzerland, has thus become the latest battleground in the geopolitical contest of wills between Mr. Obama and Mr. Putin over the fate of Ukraine.