Scientists at the Universities of Edinburgh and Glasgow developed a software algorithm to track Twitter activity.
They used it to study 51 million tweets over 11 weeks in summer of 2011 and compared these with output from news outlets for the same period.
Media houses tracked for the study included the BBC, CNN and The New York Times, which seek to set the news agenda and break news stories ahead of one another.
Scientists were able to examine Twitter messages relating to major news items. They also identified a large amount of minor news items that had featured on Twitter but had been ignored by the mainstream media, researchers said.
However, neither Twitter nor news-wires was regularly faster than the other in breaking high-profile news, researchers said.
When Twitter outperformed news-wires for speed, it was for mainly for sport and disaster-related events, their findings show.
Twitter's main benefits for news are bringing extra coverage, and for sharing news items of interest to niche audiences or with a short lifespan, such as local sports results, the study found.