Krishan was the central figure in Landmark's HotHouse programme, which co-ordinated supplier investment and best practice advice to improve the performance of independent retailers and subsequently evolved into the Lifestyle Express symbol group.
Nisa-Today's would not comment on Krishan's role with the group, other than to confirm his appointment, but his move has prompted speculation that the Today's Group will launch a similar scheme to HotHouse.
The defection comes on the eve of a major step-change in development for Landmark's symbol group programme, with a relaunch planned for the spring.
Managing director Martin Williams commented: "Lifestyle Express is now the leading symbol group within the sector and we thank Raj for his work in helping to create the foundations.
"However, in 2010 we have a major change of direction for Lifestyle Express and our Retail Redevelopment Programme. It therefore makes sense to have this clean cut-off with Raj and move the project to a freshpair of hands to deliver our ambitious vision."