Betfair is expected to report a drop in revenue on Tuesday when it reports its interims. Numis has forecast interim revenue of £183m, down from £201m in 2012, and earnings before interest, tax, depreciation and amortisation (EBITDA) of £54m.The broker recommended a 'buy' rating, saying active user growth has been encouraging, up 10% in the first quarter which is "likely to feed through to revenue". A review of the impact of commission on results also has the potential to boost revenue but tomorrow's interims may "still be too early for management to announce it has come to a conclusion", the same broker added. "The attractions of Betfair's trading opportunities are underpinned by its growing cash pile, which provides a buffer against the financial impact of negative regulatory change and could provide funding for acquisitions."Despite the strong run in the share price we believe the shares remain attractive on a FY14E EV/NOPT multiple of 15.2x."Greene King will also report its latest results amid reports that HM Revenue and Customs have urged an appeal court to throw out an attempt by the pub group to use a tax avoidance scheme involving a £300m internal loan between its companies. On the macro-economic front, UK British Retail Consortium retail sales data will be released along with Halifax house price numbers and Markit´s purchasing managers' index (PMI) for construction.Retail sales are expected to increase 1.1% in November, compare to 0.8% the previous month. House prices are tipped to rise by 0.8% in November, up from a month ago when prices grew 0.7%.PMI construction is anticipated to expand at a slower pace in November with the headline gauge slipping to 59 compared to 59.4 in October. Tuesday December 3rdINTERIMSAPI Group, Betfair Group, Daisy Group, Greene King, Northgate, Park Group, Tricorn Group, Vianet GroupINTERNATIONAL ECONOMIC ANNOUNCEMENTSAuto Sales (US) (15:00)Producer Price Index (EU) (10:00)FINALSGooch & Housego, Infrastrata, ITE Group, Pressure TechnologiesIMSSWolseleyAGMSAberdeen Asian Smaller Companies Inv Trust, ErumaUK ECONOMIC ANNOUNCEMENTSBRC Sales Monitor (00:01)PMI Construction (09:30)RD