New research from IR web solutions firm Q4 shows how US companies are increasingly turning to Twitter, the micro-blogging service, to supplement their shareholder communications.

Q4 analysed a list of 80 companies, thought to be early adopters of communication technology, and found that 55% were using Twitter for their investor relations. They noted that this figure could have been more, but that some companies, including Boeing and Foot Locker, had protected accounts, effectively vetting users.

Almost all of the 44 companies used the service to announce their quarterly results, with some providing links to webcasts of their CEOs. Bryan Smith, head of digital media, corporate communications at Rio Tinto said: “We initially trialed Twitter as a potential email alert replacement tool, but we now use it for more general corporate updates, particularly around our corporate site www.riotinto.com. This includes letting people know of new video or other content, telling them where key documents will be placed and when, and giving advance notice of important dates coming up.”

Only one other company, CGI, has joined eBay in live-tweeting during their company’s quarterly earnings conference calls

At the annual conference held by NIRI (the American investor relations trade body) earlier this year research showed that 22% of analysts were using Twitter as part of their company fact-finding.

The full research results can be found on Q4’s website.