The Federal Election Commission has dismissed Republican accusations that Twitter violated election laws in October by blocking people from posting links to an unsubstantiated New York Post article about Joseph R. Biden Jr.’s son Hunter Biden, in a decision that is likely to set a precedent for future cases involving social media sites and federal campaigns.

The F.E.C. determined that Twitter’s actions regarding the Hunter Biden article had been undertaken for a valid commercial reason, not a political purpose, and were thus allowable, according to a document outlining the decision obtained by The New York Times.

The commission’s ruling, which was made last month behind closed doors and is set to become public soon, provides further flexibility to social media giants like Twitter, Facebook and Snapchat to control what is shared on their platforms regarding federal elections.

The suppression of the article about Hunter Biden caused an avalanche of conservative criticism in October and prompted accusations that the tech company was improperly aiding the Biden presidential campaign, including a formal complaint by the Republican National Committee that said Twitter’s actions amounted to an “illegal in-kind contribution” to the campaign.

But the F.E.C. disagreed. The commission said Twitter had “credibly explained” that blocking the article’s distribution was a commercial decision and that the move followed existing policies related to hacked materials, according to the “factual and legal analysis” provided to the parties involved in the complaint.

Twitter actually reversed course within a day of its decision to block distribution of the Hunter Biden article, and its chief executive, Jack Dorsey, has called the initial move a “mistake.”

The F.E.C.’s official vote on the case — the commission is split equally between three Democratic-aligned commissioners and three Republicans — is not yet public, nor are any additional statements written by commissioners. Such statements often accompany the closure of cases and can provide further insight into the commission’s reasoning.

In addition to rejecting the R.N.C. complaint, the F.E.C. dismissed other allegations that Twitter had violated election laws by “shadow banning” Republican users, or appearing to limit the visibility of their posts without providing an explanation; suppressing other anti-Biden content; and labeling former President Donald J. Trump’s tweets with warnings about their accuracy. The F.E.C. rejected those accusations, writing that they were “vague, speculative and unsupported by the available information.”

Led by Mr. Trump, Republicans have increasingly been at odds with the nation’s biggest technology and social media companies, accusing the Silicon Valley giants of giving Democrats an advantage on their platforms.

Twitter initially said that it had prevented linking to the Hunter Biden article because of its existing policy against distributing hacked materials. The article was based on material provided by Trump allies who had sought for months to tarnish the elder Mr. Biden over his son, and focused on the Bidens’ involvement in Ukraine.

But Mr. Dorsey, Twitter’s chief executive, acknowledged in October that blocking links “with zero context as to why” had been “unacceptable.”

Soon after, Twitter said that it was changing its policy on hacked materials and would allow similar content to be posted, including a label to provide context about the source of the information.

The F.E.C. documents reveal one reason that Twitter had been especially suspicious of the Hunter Biden article. The company’s head of site integrity, according to the F.E.C., said Twitter had “received official warnings throughout 2020 from federal law enforcement that ‘malign state actors’ might hack and release materials associated with political campaigns and that Hunter Biden might be a target of one such operation.”

The F.E.C. said it found “no information that Twitter coordinated” its decisions with the Biden campaign. In a sworn declaration, Twitter’s head of U.S. public policy said she was unaware of any contacts with the Biden team before the company made its decisions, according to the F.E.C. document.

Twitter did not immediately respond to a request for comment.

Emma Vaughn, an R.N.C. spokeswoman, said the committee was “weighing its options for appealing this disappointing decision from the F.E.C.”