Police sharp-shooters had taken up positions on rooftops around the building in Tottenham Court Road when Michael Green, who barged into the building wearing gas canisters, took four people as hostages and threw objects from the fifth floor of the building.
Police negotiators entered into a dialogue with Green, who had failed to obtain a driving license thrice.
The authorities had closed the arterial Tottenham Court Road and the nearby Goodge Street tube station.
Green reportedly had a grievance against a logistics company based in the building.
The incident began around 12 noon and by 3pm, Green was seen being led away by the police. It was not treated as a terrorist incident, police said.
The police were called when computer equipment and office furniture was thrown from the office building.
The man "had a bomb and was threatening to blow himself up," witnesses claimed.
The BBC quoted an email from the Camden Council as describing the incident as "a hostage situation" in which hostages had been ordered to throw computers from the window by the suspect.
The building where news and comments website Huffington Post UK is based had been evacuated.
According to an eyewitness account, Michael Green walked into the offices of Advantage, a logistics company which offers courses in HGV (heavy goods vehicles). She said he had threatened to blow himself up before taking four hostages, including the company director.
Green had reportedly failed an HGV training course three times and wanted his money back.