Free extensions for Joomla!

Hi , thank you for your best component for generate sitemap for joomla website's. i have a website with near 80K Article and it will increase daily too . so i have a problem with google web master in i see this alert from google in my panel:

Your Sitemap contains too many URLs. Please create multiple Sitemaps with up to 50000 URLs each and submit all Sitemaps.

is there any solution for this problem? is there any way to generate multiple sitemap and set maximum article for each of them?

thank you again

is there any idea?! i very need to solotion for this problem and it very useful for many webmasters. please