The Sheffield-based group said the new five year facility will give it good visibility with funding out to October 2019.
The refinancing was secured with five banks, four of which - Barclays, HSBC, Lloyds and RBS - are existing lenders to the group.
SIG said it has entered into a new relationship with the fifth bank, Commerzbank.
The company said the new facility will ensure it has sufficient funding headroom and liquidity to support its medium-term strategic plans.
Analyst Rachael Applegate at Panmure Gordon said she expects further positive news, regarding the delivery of strategic benefits, when the group updates the market in early November.