Informa Group, the publishing and events business, could be a bid target for investors.It is thought that private equity companies Carlyle and Apax are interested in making bids. Informa Group, which is understood to be worth £1.5bn, has fallen sharply this year along with other media companies.It has been suggested that a US publishing company, or Axel Springer, Europe's biggest newspaper publisher, might be interested in puting in a bid. Informa is an international provider of specialist information and services for professional and commercial businesses.Informa has 150 sites across the globe and employs 7,500 staff in about 40 countries.