Ollie Rayner will return to Middlesex on a permanent deal next summer, while Jamie Dalrymple departs the Lord’s based county.
Rayner, who spent two spells on loan at Middlesex from former side Sussex last summer, has signed a new three year deal.
He becomes their second signing of the winter so far, after Joe Denly joined from Kent in September.
England international Dalrymple meanwhile has parted company with Middlesex for a second time having only rejoined from Glamorgan during the 2011 summer.
Both players played an important role as Middlesex gained promotion to the LV County Championship division one, finishing as division two champions.
Rayner, like Dalrymple, an off-spinning all-rounder, played in half of Middlesex’s County Championship fixtures – taking 11-wickets and contributing 266-runs at an average of 53.2.
He also displayed his magnificent catching ability collecting 14 in the championship alone.
Angus Fraser, Middlesex’s Managing Director of Cricket, spoke of his delight at completing the signing of the 25-year-old.
He said: “Ollie is an exciting and talented young cricketer who contributes with bat, ball and in the field.
“He made an extremely positive impression during the loan periods he spent with us last summer.
“As a catcher I have seen few better than Ollie behind the wicket. Several of the catches he took had to be seen to be believed.
“These catches set a wonderful tone for the side and the quality of our slip catching in 2011 had a huge influence on us winning division two.”
Dalrymple meanwhile was equally influential in Middlesex’s superb County Championship run, which saw them firmly in the promotion mix from the first game on.
The 30-year-old, who played 27 One Day Internationals and three Twenty20s for England in 2006/07, contributed 505-runs and ten wickets.
Fraser added his praise for Dalrymple’s contribution to Middlesex’s title winning season.
He added: “I have seen very few cricketers more committed or harder working than Jamie and during his time with Middlesex he set the right example to the rest of the squad.
“His leadership experience was valuable too, helping to get a young side over the line when things got a little tight at the end of the season.
However, Fraser admitted that Middlesex, are unable to offer 30-year-old Dalrymple the kind of role he would like at this stage of his career.
“Jamie’s passion lies in leadership and man management roles and these are not positions that are currently available at Middlesex.
“I'd like to take this opportunity to thank Jamie for all his input into Middlesex over the course of ten seasons in total and to wish him well for the future whether that is in the game or elsewhere.”
Middlesex will once again have a full programme of fixtures at Lord's in 2012, including action from the Friends Life Twenty20 Cup, LV County Championship and CB40. The full fixture list will be available soon.