SOLNA, Sweden--(BUSINESS WIRE)--Regulatory News: Byggmax (STO:BMAX) has signed a supplemental agreement with Handelsbanken, which will result in a SEK 50 M increase in the revolving credit facility. About Byggmax The home improvement discounter chain BYGGmax was launched in 1993 and its business concept is to be the best and most inexpensive alternative for consumers in need of high-quality construction materials. In 2007, the BYGGmax launched its business in Norway, and the first store in Finl