Called Parent Focus, the agency was formed by the National Family Parenting Institute director of comms Vicki Shotbolt and research and policy director Gill Keep, who will both quit the body next month.
The pair set up the agency on a part-time basis three months ago to work solely for parent-focused clients.
Orange will use the start-up to reassure parents that 3G phones, which allow access to the internet, are safe for children to use.
Parent Focus is advising the mobile operator on the content of booklets about the handsets.
It will also attempt to use the launch of the booklets, in September, to promote Orange as 'a responsible corporate citizen' that cares about keeping children safe.
The FSA, meanwhile, has briefed Parent Focus to provide information about its schemes to parents-to-be.
It will raise awareness about its Child Trust Fund and the advice the FSA provides on interest rates and mortgages.
The agency will begin a PR campaign about FSA leaflets at the end of the year.
'There is more awareness among organisations nowadays of the importance of parents,' said Keep.
'Parents want to bring children up the best way they can and they need information to do that,' she added.
She stressed the importance of reassuring parents about new technology.
'Parents feel less informed than their children about technology, yet it's important that parents receive proper information about modern issues that affect children,' Keep added.
The FSA was criticised by the media recently after it emerged that an estimated 70 per cent of the families who received Child Trust Fund vouchers were confused about how to use them.