The conservatorship was scheduled to end on December 31.
Sources say one reason why Brit & Co. wanted to extend the conservatorship is that it makes it easier for her to regain custody of her kids -- the family law commissioner will feel more comfortable giving her added face time if there is a safety net.
The conservators will now also be responsible for handling her business affairs and career opportunities.
As for why they suddenly asked for a permanent conservatorship -- we're told the commish doesn't want to keep extending temporary power...that it makes more sense to make the conservatorship permanent and then just lift it when Brit is safe and sound.
Under the permanent conservatorship a medical team will oversee Britney's career to make sure what she does will not compromise her mental health.
The commish said, "The conservatorship is necessary and appropriate for the complexity of financial and business entities and her being susceptible to undue influence."