Ajmal, 37, was suspended in September and has been receiving the help of former Pakistan spinner Saqlain Mushtaq to correct his action.
The Pakistan Cricket Board said he has shown “significant improvement”.
“The PCB has decided to extend Saeed Ajmal’s remedial work under Saqlain by another 15 days,” the PCB said.
“After further remedial work in the next fortnight, Ajmal shall be sent over to an high-quality lab in England for testing to ascertain the exact degree of improvement in the ace off-spinner’s action,” the body added.
Saqlain earlier this month said he wanted Ajmal to return before next year’s World Cup in Australia and New Zealand.
The ICC has been cracking down on bowlers with suspect actions, suspending five since July.
New Zealand’s Kane Williamson, Sri Lanka’s Sachitra Senanayake, Zimbabwe’s Propser Utseya and Bangladesh’s Sohag Gazi have been punished.
Bangladesh’s paceman Al-Amin Hossain was reported last month and is in danger of also being suspended. -AFP