Cross, 29, has been dropped in the latter part of this season in favour of Alex Davies, the England Under-19 wicketkeeper, who has played the last two Championship matches against Leicestershire and Gloucestershire. In 13 Championship games Cross made 409 runs at 24.05 with one hundred and two fifties.
He tweeted: "Unfortunately my time at lancs has come to end. Thanks to everyone who ever supported me and everyone I played with. Have made some amazing friends. Its now time to move on and start a fresh somewhere else. Some big points to prove. Thanks again to everyone. Enjoyed every bit of it."
Buttler's future with Somerset has been up in the air for much of the season after he was elevated to England's one-day and Twenty20 keeper, but did not keep in all formats at county level due to the presence of Craig Kieswetter at Taunton. When asked during the one-day series against Australia, Buttler admitted it had been a bit of a distraction for him but hoped progress would be made soon.
Cross had to bide his time for a regular first-team slot after beginning his career while Warren Hegg was the No. 1 at Old Trafford. Luke Sutton's arrival meant he had to wait even longer before he became the main keeper for Lancashire's Championship-winning season in 2011 although had been in the one-day role for some time.
Cross is the second senior player Lancashire have released in recent days following the departure of Stephen Moore.