(ShareCast News) - Media group RELX, formerly known as Reed Elsevier, posted a 3% jump in underlying revenue growth in the first nine months thanks to a strong performance from its risk and business information unit, as it reaffirmed its outlook for the full-year.RELX posted underlying revenue growth of 7% in its risk and business information division, 2% growth in its scientific, technical and medical unit and 1% in the legal business.The risk and business information unit saw strong revenue growth across all key segments, driven by volume growth and the roll-out of new products and services.RELX said the customer environment in Scientific, Technical & Medical remains largely unchanged. Key business trends remained positive in the first nine months and it continued to see strong growth in article submissions and usage in primary research, while print book declines continued in line with the prior year.In Legal, RELX said market conditions in the US and Europe remain stable and electronic revenue growth was partially offset by print declines.The company, which said it was confident 2015 will be another year of underlying revenue, profit and earnings growth, acquired 14 content, data and exhibition assets year to date for a total consideration of £919m. It also disposed of 11 assets for £72m.RELX said it completed £425m of the previously announced £500m share buyback, with the remaining £75m to be deployed by year end.