It is the first time the Dublin-headquartered company has brought in a PR agency and comes ahead of the launch of several new projects at the end of this year and at the beginning of 2007, details of which remain under wraps.
The company also intends to refresh its corporate profile via a Tion-run campaign.
Red Circle, established in 1999, has offices in London, Spain, the Philippines and Ireland.
Last year, it had a turnover in excess of £16m and was the largest spender on premium-rate advertising in the UK.
Tion London will initially concentrate on building the company's profile in the trade press, targeting publications such as Mobile Marketing, Mobile Entertainment and Revolution before moving on to the national business pages.
‘We want to promote Red Circle as a leader in the mobile-content sector and will be running a campaign based on research, trend monitoring and developments in the market,' said agency creative partner Siobhan McGeady, who leads the account.
Mobile content is a major new-media growth area - a report from Analysys estimated that by 2011 the market in western Europe alone would be worth £15.7bn.
Last month, News Corp paid £100m for a stake in content creator Jamba.