W has been brought on board by the market leader following a pitch for a new brief thought to revolve around growing its player base in the UK.
A source close to the pitch process said the work would revolve around "repositioning it as a lifestyle brand, and broadening the appeal beyond its traditional market".
"This would take it into areas like music, the arts and a wider lifestyle space," they said, "and things more interesting to a wider audience than the traditional poker player."
The brief is also thought to include PokerStars stablemate Full Tilt Poker, both of which are owned by The Rational Group.
Industry estimates put the brands' share of online poker traffic at around 55 per cent.
However, the UK online poker sector is set to face scrutiny over the risk of addiction with a government-commissioned study into fixed-odds betting terminals apparently set to expand to include online gambling.
"This is less about trampling on competition and more about uplifting the whole category through getting more numbers into the online poker space," the source added.
Both W, which has worked with Poker Stars previously, and The Rational Group declined to comment.