LONDON — The 2013 Olivier awards will take place on April 28 at the Royal Opera House, it was announced Friday by the Society of London Theater.Nominees for London’s leading annual legit kudofest will be announced on March 26 with a March 5 cut-off. In contrast to the Tony awards, which are chosen by more than 800 voters across the industry, the Olivier judging panel for theater numbers just nine voters. Last year’s panel saw more than 80 shows in contention for the awards as compared with the Tony voters, who saw just 37. Expectations of the number of London shows for 2013 consideration are equally high. All further details about the ceremony are under wraps until January.