(ShareCast News) - Advertising giant WPP is on Wednesday expected to report a 20% increase in first-half pre-tax profit.Numis estimates pre-tax profit of £590m, up from the previous year's £491m. The broker predicts a 2.2% increase in like-for-like sales in the first half, with 2.5% growth in the first quarter and 2% in the second.In a June AGM statement, WPP said its like-for-like sales rose 2.3% in the first four months of the year with growth across all regions, particularly in the UK and the Asia Pacific.The group said following solid 2014 results performance in the first four months of the new financial year had been "particularly creditable", as worldwide GDP growth seemed to have slowed.Numis analyst Paul Richards, said: "At the AGM, WPP stated that it had delivered a strong margin performance in the first four months and it is firmly on track to at least achieve its target of 30 basis point margin improvement."But he added that recent forex moves will provide a modest headwind to reported full-year results. "The group's peers have already reported results, which we view as robust (H1 organic growth, +5.2% for Omnicom, +6.2% for Interpublic) or reflect company specific issues (Publicis +1.2%)."Numis retained an 'add' rating and target price of 1,725p.Wednesday 26 August UK ECONOMIC ANNOUNCEMENTS CBI Distributive Trades Surveys (11:00) Services Producer Price Index INTERNATIONAL ECONOMIC ANNOUNCEMENTS Crude Oil Inventories (US) (15:30) Durable Goods Orders (US) (13:30) MBA Mortgage Applications (US) (12:00) INTERIMS Anglo Pacific Group, Bioquell, Cape, Carillion, Frontline Ld, HSS Hire Group , NMC Health, Optimal Payments Plc, Paddy Power, PJSC Magnit GDR (REG S), Skyepharma, Vimetco NV GDR (Reg S), WPP Q2 Frontline Ld, MHP SA GDR (Reg S) GMS Motive Television INTERIM DIVIDEND PAYMENT DATE Aberdeen UK Tracker Trust INTERIM EX-DIVIDEND DATE First Quantum Minerals Ltd. AGMS Coral Products, Great Eastern Energy Corp Ltd. GDR, IGas Energy, Iomart Group, Latham (James), Livermore Investments Group Ltd., New Century AIM VCT, Ovoca Gold, Oxford Technology 2 VCT, Oxford Technology 3 VCT, Oxford Technology 4 Venture Capital Trust, Oxford Technology VCT