This excerpt taken from the MBI 10-Q filed Aug 8, 2008.
Under certain non-insurance derivative contracts entered into by the Company, collateral postings are required by either MBIA or the counterparty when the aggregate market value of derivative contracts entered into with the same counterparty exceeds a predefined threshold. Cash or securities may be posted as collateral at the option of the party posting the collateral. As of June 30, 2008, the Company held cash collateral of $299 million from derivative counterparties and had posted cash collateral of $0.9 million to derivative counterparties related to swap transactions primarily comprised of economic hedges of investment agreements and medium-term note (MTN) liabilities.
The Company reports cash received or posted in its Consolidated Statements of Cash Flows as either operating, investing or financing consistent with the classification of the asset or liability that had created the posting requirement.