The sportswear brand will supply team kit, replica kit and training equipment in a two-year deal starting from the beginning of the 2010/2011 season.
The kit deal follows the extension of the club’s shirt sponsorship deal with nationalised bank Northern Rock.
The firm will remain the Championship club’s shirt sponsor until the end of the 2013/14 season after signing a four-your extension worth up to £10m.
The firm’s continued sponsorship of the club, which began in 2004, has attracted criticism from some investors after the Government pumped £2.4bn and provided a £20bn loan after the run of the bank in 2007.
The UK Shareholders Association, which is representing the interests of investors that lost money when the bank was nationalised, says although the deal was “technically irrelevant” in the legal battle to recover the shareholders’ losses, it did add to its case on “moral level”.
Northern Rock has defended the new deal, arguing that it remained “mindful of our responsibilities under Government ownership”, adding that and only considered “those advertising and promotion channels that deliver a high return on investment and good strategic fit.”
Championship leaders Newcastle are looking to bounce straight back into the Premier League after being relegated last season.
Owner Mike Ashley has been looking for ways to boost commercial revenues. It recently renamed its St James’ Park home ground sportsdirect.com@St James’ Park Stadium until the end of the season or until a new sponsor can be found to “showcase” the stadium to potential naming rights partners.