A jury ended its first week of deliberations Friday apparently deadlocked on at least one of the counts charging a Long Island-reared investment banker with illegally passing his father insider trading tips worth $1.1 million.

Halfway into the fourth day of deliberations, the foreperson sent a note Friday to the judge saying that a unanimous verdict “may not likely happen” on each of the nine counts against Sean Stewart, 35, formerly of North Merrick.

“They believe they’re deadlocked,” U.S. District Judge Laura Taylor Swain in Manhattan said from the bench. The judge instructed the panel’s eight women and four men to “continue that hard work” and keep deliberating, as they have since Tuesday.

“No other jury will ever be in a better position than you to reach a decision on this body of evidence,” she said, reciting what is known as an Allen charge, a formal admonishment about their duty to reach consensus. Allen charges, approved by the U.S. Supreme Court since 1896, are standard in many jurisdictions when a jury reports being deadlocked.

The counts against Stewart include conspiracy, wire fraud and securities fraud.

Sean Stewart’s father, Robert Stewart, 61, of North Merrick, has admitted profiting from information about pending mergers and acquisitions about which his son knew inside information because he was an investment banker on the deals.

advertisement | advertise on newsday

Sean Stewart faces up to 20 years in prison if convicted.

The jury’s note, sent out shortly after noon, said, “If the jury is at an impasse on a particular count, which we cannot resolve, does that mean that we have to render a not-guilty verdict, as the government has not met its burden of proof for some of the jurors? Or do we render a ‘no decision’ vote? There is no option on the verdict sheet for a ‘no decision’ option. Do we continue to deliberate until we come up with a unanimous decision, which may not likely happen?”

The judge told jurors that a partial verdict is allowed, but urged them to keep deliberating on any unresolved count.

Stewart, a scholar-athlete who attended Kellenberg Memorial High School and Yale University, is accused of telling his dad about deals involving five health care mergers and acquisitions between 2011 and 2015. The father, an accountant, and a trading partner to whom the elder man passed tips, Richard Cunniffe, have pleaded guilty.

Stewart testified that he discussed his work with his dad, in violation of his duty to then-employers JPMorgan Chase & Co. and Perella Weinberg Partners. He said he did so only as a way of bonding with his father, whom he trusted not to trade based on their conversations.

The younger man continued to discuss the matters with his dad even after regulators in 2011 flagged his father’s trading as potentially connected to his son’s insider knowledge.