More investment in a new online trading system hit profits at stamp collecting group Stanley Gibbons.Gibbons said adjusted pre-tax profits in the six months to December 31st came in at £3.8m, down on the £4.1m achieved in 2012. Adjusted pre-tax profit in the 12 months to December 31st was £5.6m against £6m a year ago.The group said testing of the core features of its new online platform will begin next month with a view to launching it in the second half of 2014.Gibbons said trading profits rose 9% to £4.6m for the six months to December 31st 2013 and lifted 9% to £6.9m in the 12 months to December 31st. The group "substantially strengthened" its auction services with the acquisitions of Noble Investments last year, plus British Commonwealth King George VI stamp dealer Murray Payne.Chairman Martin Bralsford said: "The group's strong balance sheet position including net cash of £17.3m and a high quality stockholding of rare stamps and collectibles stated at a historic cost of £30.6m provides a substantial capital base from which to invest in further growth opportunities."Gibbons increased the total dividend for the year to December 31st by 8% to 7p.Shares rose 1.5p or 0.4% to 339p at 08:44 in London.PW