Ladbrokes' chief executive Richard Glynn will need to show investors that his strategy to turn the British bookmaker around is working when the company reports its first half results on Tuesday.Glynn needs to prove that its new digital platform worked well through the World Cup and had helped the company regain customers, a top 10 shareholder told The Sunday Times. A spokesman declined to comment. In February the group said it was taking longer than expected to switch its gaming products to a new online system, which is expected to hurt first half profits. "There were, however, some encouraging signs of success with the first quarter trading statement; stakes on mobile sportsbook were up 95% for example," Numis said."Nevertheless, Ladbrokes first quarter trading statement was the weakest of its peers with group net revenue down 5.1%; down 2.3% in UK retail and down 18% online."The broker said the World Cup should have helped second quarter profits and estimates £138m (consensus £135m), which will depends on a considerable turnaround.Ladbrokes has promised to maintain a full year dividend of 8.9p for full-year 2014, which represents a yield of 7%."This may provide some support for the share price. However, the shares have fallen since the dividend commitment was made reflecting, perhaps, the deteriorating regulatory environment as much as any company-specific concerns," Numis added, giving the company a 'hold' rating. Meanwhile, troubled outsourcing giant Serco will also report its interim results on Wednesday. Numis recommended a 'reduce' rating ahead of the figures, pointing to a "number of loss-making contracts, additional contract provisions, and reduced profitability from retained certain contracts".Numis forecasts profits have plunged from £106m in the first half of 2013 to a loss of £11mn over the same period in 2014.Serco last year agreed to repay about £68.5m to the government for overcharging on contracts to tag criminals in the UK. The company was accused of charging the government for tagging people who were either dead or in jail. Tuesday August 12thINTERIMSAL Noor Hospitals Group, Damac Real Estate Development Limited GDR (Each Repr 3 Ord) (Reg S) , Ithaca Energy Inc. (DI), Just Eat , Ladbrokes, Prudential, Serco Group, SIG, ZotefoamsINTERNATIONAL ECONOMIC ANNOUNCEMENTSTreasury Budget Statement (US) (19:00)ZEW Survey (EU) (10:00)ZEW Survey (GER) (10:00)Q2Ithaca Energy Inc. (DI)GMSBroca, Lebanese Co for the Development & Reconstruction of Beirut Central District SAL GDS (Reg S)FINALSMiradaANNUAL REPORTDiageoAGMSGB Group, Global Lock Safety (International) Global Lock Co Ltd. (DI)TRADING ANNOUNCEMENTSVolution Group (WI)UK ECONOMIC ANNOUNCEMENTSBRC Sales Monitor (00:01)Public Sector Finances (09:30)FINAL DIVIDEND PAYMENT DATEBabcock International Group, Invesco Asia Trust, KBC Advanced TechnologiesRD