Partick Thistle have completed the signing of Adam Barton on a three-year deal from Portsmouth for an undisclosed fee.

Barton, who is renowned for his range of passing, has primarily played as a central midfielder but has latterly been used as a centre-half by Pompey manager Paul Cook.

The 25-year-old from Clitheroe has been capped at full international level by Northern Ireland, after previously turning out for the Republic of Ireland at under-21 level.

Barton started his professional career at Preston North End and was loaned to Crawley Town before moving on to Coventry City in 2012.

He was loaned to Fleetwood Town after falling out of favour under manager Andy Thorn, but returned to establish himself at the Ricoh Arena under Steven Pressley and Tony Mowbray before moving on to Fratton Park last summer.

Meanwhile, striker Mathias Pogba and goalkeeper David Crawford have both left Firhill by mutual consent.

Pogba has struggled to break into the Thistle starting eleven since joining the club, scoring just two league goals – both against Hamilton – and once in the League cup against Stenhousemuir.

Former Alloa keeper Crawford had been brought in by Alan Archibald during the summer due to injuries to first-choice Tomas Cerny and understudy Ryan Scully, and played in the League Cup group stages.