The Braveheart star and Grigorieva finally reached a custody agreement over their one-year-old daughter Lucia last week (26Aug11) and the two met again in court on Tuesday (31Aug11) to discuss the financial implications of the settlement.
Details of the deal, obtained by TMZ.com, indicate Gibson will give Grigorieva the money in three equal installments of $250,000 (£156,250) over the next five years. The actor is said to have made the first payment on Tuesday and he'll pay the final sums in 2013 (15Sep13) and 2016 (01Jan16).
The former couple will also share joint physical and legal custody of their little girl, and Grigorieva will maintain ownership of her current home until the child turns 18. The residence must then be sold off, with all proceeds going directly into a trust fund for Lucia.
Additionally, Gibson will be responsible for paying maintenance fees on the home - on repairs of up to $5,000 (£3,125).
Los Angeles Superior Court judge Peter Lichtman also mandated that neither star be allowed to disclose details about the other party.
Gibson and Grigorieva split early last year (10) and were locked in a bitter dispute over the child until earlier this year (11).