Porta Communications, the AIM-quoted marketing and communications business, has increased its holding in Thirteen Communications from 30 per cent to 51 per cent. The firm paid £350,000 for the increased stake, which will be satisfied by the issue of 2.69 shares at 13p each. Group Chief Executive, David Wright said: "In September this year, Porta took a 30% holding in Thirteen in exchange for start-up capital, including office related costs, with an option to take a controlling interest over the next two years. "However, after less than two months trading, the success of Thirteen in both new business brought in and in joint pitches with Newgate, prompted the decision to bring forward the group's plan for ownership."Thirteed was established to offer a range of consultancy services rooted in consumer and corporate public relations. NR