The 28-year-old was voted their 2018 Player of the Year, having taken 61 wickets at an average of 20.54 as the county finished fourth in Division Two
Middlesex have announced that fast bowler James Harris has agreed a long-term contract extension which will keep him at the county until at least the end of the 2021 season.
The 28-year-old was voted their 2018 Player of the Year, and joined the county from Glamorgan in 2014.
Since joining, he has taken 250 wickets in all formats in just over 100 appearances and enjoyed a fantastic 2018 at odds with the fortunes of his county.
He finished the season their leading wicket-taker with 61 wickets at an average of 20.54 as they finished fourth in Division Two.
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"I am thrilled to sign an extension to my contract with this great club," Harris said.
"I have loved my time playing here to date and am very excited about the next three years."
Middlesex's managing director of cricket, Angus Fraser added: "During a difficult year for the club James was outstanding in 2018.
"I am delighted he has furthered his commitment to Middlesex. As well as being a fine cricketer he is a top man. Every club in the country would want a number of players possessing his characteristics and values."
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