Telecoms group IPPlus hailed progress in its call centre business but launched a review of its document storage arm after difficult trading.IPPlus said its Ansaback contact centre operation lifted first-half revenue by 37% in the six months to December 31st despite increasing staff to help it secure bigger contracts.The group's call centre software business, CallScripter, had a harder-than-expected first half due to delays in securing larger deals.Its IP3 Telecom telephony services business boosted revenue by 18% against a year ago, with new business contracts exceeding management hopes.But the company's Ancora Solutions document storage and disposal arm faced difficulties with revenues falling from last year's record six-month sales and returning to more modest 2011 levels, prompting IPPlus to review it."Trading remains tough with private sector companies reluctant to move and invest in new buildings and plant. In view of its poor performance, the directors are considering the options to develop and review this division," the group said.Pre-tax profit rose to Β£613,984 from Β£174,732 last time on revenue of Β£4.7m, up from Β£4.06m a year ago.IPPlus said difficult trading conditions were likely to continue throughout 2014, but added: "Nevertheless the board looks forward to reporting further progress."Shares in IPPlus fell 1.25p or 4.5% to 26.75p at 16:11 in London. PW