Britney Spears will reportedly pay her ex-husband Kevin Federline $20,000 a month to care for the former couple's sons - an increase from $15,000.

The pair finally reached an agreement on the care of their two young sons on Thursday, following a bitter 18-month custody battle.

Under the new deal, Federline retains sole custody of Sean Preston, two, and Jayden James, one.

But it has emerged Federline will also receive additional child support in the settlement.

Spears, 26, maintains her visitation rights - with two visits and one overnight stay allowed each week - and she may also be granted an additional overnight stay by the end of the year.

A source tells People.com, "All Britney was seeking was a formalisation of her increased visitation that she's obtained over recent weeks, and the additional overnight. She won both of those requests."

It has also been reported Federline's lawyer, Mark Vincent Kaplan, received $250,000 for his work on the case.