The Royals' home and away shirts will carry the supermarket's branding in all matches during the 2011/12 and 2012/13 seasons.
Reading commercial director Pat Coyne said: "We are absolutely delighted that Waitrose have extended their contract with us.
"Our partnership to date has been very successful and we are looking forward to continuing that for a further two years at least.
"We share the same brand values, together, we are very proactive in a number of joint initiatives, especially engaging with fans in the local community. We are proud to wear the Waitrose logo on our shirt."
A Waitrose spokesman added: "We're delighted to extend our commitment to Reading Football Club."
Source: PA
Source: PA