Lander, who reports to Woolworths CEO Trevor Bish-Jones and chairman Gerald Corbett, steps down on 2 June after four and a half years at the group.
Internal comms will shift to HR, while Bish-Jones will oversee investor relations alongside Tulchan Communications until Woolworths appoints a finance director.
Licensing of its Ladybird childrenswear brand and CSR transfer to marketing.
Fleishman-Hillard's public affairs work for the firm will cease when Lander leaves.
The firm is considering making one of its comms team head of PR under the remit of marketing director Stephen Robertson.
Sales are around five per cent down as supermarkets increasingly encroach on its territory. Last month, private equity group Apax Partners pulled its bid for the chain, wiping £200m off its market value.
In a statement issued to PRWeek, Bish-Jones said: 'Nicole's skills have been invaluable to the company and we are desperately sorry to see her go.' Lander said: 'I have already had a number of interesting discussions and will be making a decision (on my future) soon.'
Lander was voted PRWeek's PR Professional of the Year in 2003.