Marks & Spencer has approached two children's charities to help it launch a bra-fitting service for girls.
The retailer consulted Kidscape and the NSPCC to avoid problems in the design and fitting of underwear for under-16s.
Michele Elliott, director of Kidscape, said: "Several large companies have run into difficulties with issues such as marketing frilly knickers to girls as young as nine and selling them thongs.
"M&S want its products to be good quality and pretty without being suggestive and we were able to advise them on that.
"Also children can get embarrassed in changing rooms where adults need to be aware of how they touch them or whether they should be allowed to go in."
The two charities developed a set of guidelines for fitters and store management teams before it unveiled the Angel range of first bras. The bras, which will be on sale in 100 M&S stores, contain Kidscape endorsement labels.
Rosemary Gordon, head of consultancy at the NSPCC, provided diagrams for girls with English language difficulties, a Braille version of the fitting procedure for blind or partially sighted customers and an audio tape for those who are hard of hearing.
The NSPCC also advised on safety issues such as vetting new staff and ensuring that there were no men present in the lingerie department. "It helps relieve the embarrassment factor if customers have a confident fitter," said Gordon.
The NSPCC has helped 290 organisations develop best practice in child protection since 1999.
Melissa Wilson, marketing manager at M&S, said: "The NSPCC advice helped us to develop procedures to ensure customers under the age of 16 feel at ease with our measuring procedures while making their parents feel reassured that their daughters are being dealt with sensitively."