The 32-year-old will join former Zimbabwe Test batsman Murray Goodwin on the staff at Hove.

Mushtaq has previous county experience with Somerset, and also played two Championship games for Surrey this summer while compatriot Saqlain Mushtaq was away in Morocco with the national side.

"His commitment to come back and prove he is still one of the world's top flight spinners came across loud and clear, and a hungry man with talent is one to watch," said Sussex Cricket Manager Peter Moores.

Mushtaq has taken 183 wickets in 50 Tests, the last against New Zealand in March last year and was one of Wisden's five Cricketers of the Year in 1997.

He has also made 143 one-day appearances and was a member of the Pakistan team which beat England in the 1992 World Cup final in Australia.

The decision to join Sussex could help revive his international career, although the Pakistan selectors now regard Saqlain and Danish Kaneria as their first-choice spin bowlers.

Sussex are currently fifth in Championship Division One, but may need to win their final game against Warwickshire to make absolutely certain of avoiding relegation.

They have offered contract extensions to all-rounder Robin Martin-Jenkins, off-spinner Mark Davis and wicket-keepers Matt Piro and Tim Ambrose and have also agreed a new two-year deal with Kevin Innes.