The study which looks into how Britain uses social media shows that LinkedIn has become the most popular social media channel for FTSE 100 companies.
Nearly 90 organisations are actively using accounts to connect with 1.9 million people on the site.
Between December 2011 and June 2012 the number of users on LinkedIn connecting with FTSE 100 companies grew by 35% resulting in two users per second connecting with FTSE 100 companies on LinkedIn.
Unilever boasts 225,476 followers on LinkedIn, followed by HSBC with 158,625 and Royal Dutch Shell with 158,467.
"Our update to the FTSE100 Social Media Index reveals the large and growing circle of influence that FTSE100 companies have created online," says Cathal Smyth, managing director at The Group.
"LinkedIn is clearly becoming an essential channel for businesses wishing to connect with important audiences and in particular it has become an important aspect of corporate recruitment."
Larger British companies are also beginning to gain a large Twitter following. According to the study FTSE 100 companies have seen a 70% jump in followers on Twitter within the last six months resulting in 1.7 million users now following FTSE 100 companies on Twitter.
The number of fans on corporate Facebook pages has jumped 35% since December 2011 and views of corporate YouTube videos have increased by 79%.
Social sites like Google+, however, have proven not to be popular amongst companies. Out of 50 registered FTSE 100 accounts only 12 companies actually use them on a regular basis.
Blogging is also an underused social medium by companies. The number of FTSE 100 companies remained the same since last year at 16 while the number of blog posts fell by 45%.
While companies may be more attracted to popular social media sites corporate blogging has its benefits.
"Companies’ are really missing an opportunity by neglecting this channel, as it offers the FTSE100 a real opportunity to engage with stakeholders, demonstrate transparency and lead on issues," says Smyth.
