Sussex have agreed new two-year contracts with seamers James Anyon and Chris Liddle.
Anyon, 28, moved to Hove from Warwickshire in 2009 and has cemented a regular first-team place, taking 25 wickets in the LV County Championship this season.
Liddle, 27, has been used primarily in the one-day side this season after putting two years of injury problems behind him.
Both have now committed until the end of the 2013 season, and cricket manager Mark Robinson said: "Jimmy and Chris have both had very good first halves of the summer.
"We also believe as a club that their best is still to come. Both are beginning now to grow in confidence, and beginning to feel more comfortable in their roles.
"This extra security should allow them to do that. They should continue only to improve as cricketers and develop into potential match winners for the future."
Anyon added: "I'm delighted to have signed a new contract and I'll be looking to finish off this season as well as it has started for me."
