The pitch is being run through the AAR. It will see the incumbent, the Leeds agency Phillipson Ward Longworth Camponi, and HHCL/Red Cell, which handles the core Sky creative account, pitch against two further agencies.
It is understood that the AAR is initially seeking four agencies that it will shortlist to two for the final pitch.
PWLC and the new-media agency DS Emotion were only appointed to handle the Sky Bet account last October.
The pitch is not thought to affect media planning and buying, which is held by Universal McCann.
It is understood that Sky is looking to ramp up the advertising presence of Sky Bet to raise public awareness of the wide variety of options that the betting service offers.
Sky Bet operates betting services across fixed-line telephone, online, via mobile and on interactive television via Sky Active.
The real-time nature of interactive television betting allows viewers to place bets on a range of possibilities as they happen - from the outcome of a particular free kick in a football game to entertainment options such as evictions on a reality TV show.