Ben Phillips took the decision to leave Somerset and join Nottinghamshire because he faced being used as a one-day bowler only in 2011.
The 36-year-old seamer had a year left to run on his contract at Taunton and was under no pressure to leave, but could see the writing on the wall following the signings of Steve Kirby and Gemaal Hussain.
Phillips said: “I wasn’t actively seeking a move, but it was clear my opportunities might be limited at Somerset next season.”
And Somerset director of cricket Brian Rose confirmed: “Ben now has the chance to play first-class cricket for at least a couple more seasons whereas his chances with us would mainly have been in the one-day game.”
Rose was full of praise for Phillips, who had his best season with Somerset this year after being troubled by injury following his move from Northamptonshire in 2007.
“Ben has been a valued member of the side and people here will miss him,” said Rose. “We are pleased that he has been able to secure such a good move, albeit to one of our main rivals.”
Somerset have now effectively brought in Kirby for Phillips and Hussain for Mark Turner, who left at the end of the season to join Derbyshire.
With Charl Willoughby and Alfonso Thomas still at Taunton, Phillips would have been no higher than fifth choice seamer. He took 29 LV=County Championship wickets at at average of 22.7 last summer.