By Brendan Pierson

NEW YORK (Reuters) - Judges in a federal appeals court on Thursday sharply questioned whether the corruption conviction of Sheldon Silver, former speaker of the New York State Assembly, could stand in light of a recent U.S. Supreme Court decision.

During oral arguments before the 2nd U.S. Circuit Court of Appeals in Manhattan, Silver's lawyer, Steven Molo, said the jury in Silver's case was wrongly instructed, citing the Supreme Court's later overturning of the corruption conviction of former Virginia Governor Bob McDonnell.

In McDonnell's case, the Supreme Court ruled last June that routine political activities like arranging meetings generally were not "official acts" that could give rise to a corruption conviction.

Silver, a Democrat, is appealing his November 2015 conviction and 12-year prison sentence for fraud, extortion and money laundering.

Molo said Silver's jury was given an older, broader definition of corrupt acts, and told that any one of a long list of alleged acts by Silver - including meetings and other communications - was enough to convict.

Assistant U.S. Attorney Andrew Goldstein, arguing for the government, said that Silver's case was "nothing like" McDonnell's and that the evidence "overwhelmingly established" that Silver abused his power.

Prosecutors said Silver awarded state money to a prominent cancer researcher who in turn referred asbestos patients to Silver's law firm. They also said he steered two real estate developers to a friend's law firm while supporting their interests on rent legislation.

During Thursday's oral argument, U.S. District Judge William Sessions of Vermont, a visiting judge on the panel, pressed Goldstein to explain how the court could know the jury's reasoning.

Later, Circuit Judge Richard Wesley questioned whether some of Silver's alleged actions, like advising a real estate developer go to his friend's firm, were criminal.

"Then any powerful person who asks someone to do something is committing a federal crime?" Wesley asked.

Goldstein said that Silver's power generally allowed him to pressure others, but conceded that, for some of the government's claims, there was no evidence that he directly threatened to use that power.

A win for Silver could bode well for former state Senate Majority Leader Dean Skelos, who was convicted on corruption charges shortly after Silver. Skelos, a Republican, is appealing his conviction and five-year sentence.

The two convictions were major victories for former U.S. Attorney Preet Bharara, who was fired this week by the administration of President Donald Trump, a Republican, after refusing to resign.

(Reporting by Brendan Pierson in New York; Editing by Noeleen Walder and Dan Grebler)