By Alex Dobuzinskis

LOS ANGELES (Reuters) - Singer Britney Spears will pay $20,000 a month in child support to ex-husband Kevin Federline for the care of their two children and will make a final payment of $250,000 to his lawyers, according to a final custody agreement filed in court on Friday.

The monthly child support payment is a $5,000 increase over what Spears and Federline, a dancer and rap singer, agreed to last year, the court papers showed.

The agreement formally settles the custody case between Spears, 26, and Federline, 30, said Allan Parachini, a spokesman for the Los Angeles Superior Court.

The custody portion of the settlement was not made public. In an order filed on Friday, an August custody trial for the case was called off.

Federline's attorney, Mark Vincent Kaplan, last week told several media organizations the agreement would allow Federline to retain sole custody of his children with Spears -- Sean Preston, 2-1/2, and Jayden James, 22 months.

Kaplan and Spears' attorney, Laura Wasser, did not return calls on Friday.

Spears' $250,000 payment for Federline's legal expenses is due July 30.

Spears and Federline married in 2004, split up in late 2006 and their divorce was finalized last year. Spears lost custody of the boys in January after two brief hospitalizations for psychiatric evaluation.

During the divorce and custody battle last year, Spears displayed increasingly bizarre behavior in public such as shaving her head and going after the paparazzi with an umbrella.

But Spears in recent months has been credited with turning her life around and last month she was given court permission for overnight visits with her sons.

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