''Murali Kartik is a hugely exciting signing for the club. Over the past few seasons, we have lacked an International class spinner and are delighted to have addressed that with Kartik.
''He is a popular signing with our players and I am sure he will quickly become a favourite with our supporters,'' Middlesex Chief Executive Vinny Codrington said in a statement.
Middlesex never had a quality spinner since Phil Tufnell and the club now pins its hopes on Kartik, who has been in and out of the Indian team.
The spinner has had some success in county cricket with two stints with Lancashire in the last two seasons.