Stores in Bluewater, Brighton, Cambridge, Canterbury, Cardiff, Derby, Edinburgh, Kingston, Leeds Trinity, Maidstone, Northampton and the Silverburn Glasgow branch are to be closed.
It is thought 130 staff in total have been put on notice, though no formal redundancies have been made.
This comes on top of the six shut earlier this week, which resulted in 75 redundancies.
Administrators PricewaterhouseCoopers, who were appointed earlier this month, are still seeking a sale of the remaining stores, although it is thought that a gradual wind-down is more likely.
Robert Moran, Mike Jervis and Stuart Maddison of PwC were appointed as joint administrators of Marnixheath, the holding name of La Senza and yoghurt retailer Pinkberry, on 1 July 2014.
Moran said: “We have worked closely with the La Senza brand owner to assess the expressions of interest made regarding the brand. These discussions remain ongoing, however, the difficult decision has been made to close a further 12 unprofitable stores over the coming weeks.
“We are working closely with the employees of the stores impacted and supporting them as much as possible at this difficult time.
“There has been significant interest from other retailers regarding the property estate and we are exploring all options regarding potential sales.”