Extending local phonebook

Hi,
I am working on T22P and need to use local phone book which will be updated by autoprovisioning. Everything works perfect (updatind, searching etc...) the only problem is capacity. I need to load 1000 contacts and it is said that only 300 is possible. Is there any way to extend this local phonebook? Maybe newer firmware allows it? I work on firmware 7.61.0.80.

Thank you for your support.