The connection between Castell Howell Foods and the Scarlets goes back several years and the company was a shirt sleeve sponsor last season.
The new sponsorship agreement takes Castell Howell Food's support of the Scarlets to a higher level as the region gets set to move into its new world-class 15,000 capacity stadium in November 2008.
The Castell Howell Foods south stand is the largest of the four stands within Parc y Scarlets with a capacity of 5,748 seats and houses all the hospitality boxes as well as the Carwyn James sponsors lounge, the Phil Bennett lounge (debentures) and the Quinnell Lounge (business club) and the Delme Thomas public house.
Castell Howell Foods will have a large exterior and interior branding presence on the south stand denoting their sponsorship as well as additional main sponsor benefits.
Gareth Davies, Managing Director of the Llanelli Scarlets said: "We have retained a great partnership with Castell Howell Foods over many years and this major sponsorship is a huge step forward that cements our connection with the highly successful Carmarthenshire-based business. We are very grateful for the company's continued support of our region."
Kathryn Jones director of Castell Howell Foods said: "For more than a decade we have been focused on supporting our community and remaining close to our roots in West Wales. The Scarlets are a major name and force within this area and we look forward to a successful partnership over the next five years with one of the most celebrated and high profile rugby regions in Wales.
"This is a very impressive new stadium in Llanelli which will not only boost the Scarlets as they go forward but it will also be of benefit to a wide-range of people and sports clubs in the area thanks to the associated community facilities.
"We are delighted and very proud to be a main sponsor of the new Parc y Scarlets stadium and to continue our support of the Llanelli Scarlets in this new chapter in the region's history."