London is expected to start the day with its best foot forward, buoyed by two of the morning's big results announcers upping earnings guidance. City traders expect the Footsie to open around 20 points up from last night's close.Publishing giant Pearson said 2010 earnings will be ahead of previous guidance, as all of its major businesses sustained their strong trading momentum throughout last year.The firm expects full year operating profits to come in around 20% higher than 2009's level, at about £850m. Earnings per share are expected to be 76p, ahead of previous guidance of 72p, and up by about 16% on the 65.4p figure for 2009.Bookmaker William Hill confirmed full-year results would be at the top end of expectations as strength in the online business and gaming machines during the fourth quarter made up for weather-hit sports fixtures. The positive trends of the previous quarter continued into the final 13 weeks of 2010 when retail turnover grew 8% despite the snow capping December's figure at 4%. Almost half all UK horseracing meetings were cancelled last month and one weekend at almost no football at all.Property giant Land Securities reports good lettings across its London and Retail portfolios over the past three months. Voids in the like-for-like portfolio were down 5.7% in the quarter to December (5.9% in the previous three months). The void level includes units let on a temporary basis at 1.2%. A further 0.6% is under offer. Units in administration wre down slightly in the like-for-like portfolio at 0.3%.