Goldman (GS) will pay $300 million in fines and $250 million in restitution to investors harmed by its misconduct in the 2007 subprime debt deal, the Securities and Exchange Commission said.

    The penalty is the biggest ever assessed a Wall Street firm, the SEC said. But it is far less than the $1 billion or so Wall Street was openly discussing, and Goldman shares climbed.

    Goldman didn't admit or deny the SEC's charges, but acknowledged its marketing materials were incomplete. The firm said it "regrests" it failed to disclose the role of a short-seller who made $1 billion betting against the 2007 Abacus deal.

    "This settlement is a stark lesson to Wall Street firms that no product is too complex, and no investor too sophisticated, to avoid a heavy price if a firm violates the fundamental principles of honest treatment and fair dealing," SEC enforcement chief Robert Khuzami said.

    News of the settlement sent the stock up 4% to $151 in after-hours trading Thursday, its highest level since May. Goldman shares traded in the mid-180s before the SEC announced its case April 16.

    As a result of the settlement, Goldman will send $150 million to German bank IKB and $100 million to Royal Bank of Scotland (RBS), which acquired a Dutch bank that was backing troubled bond insurer ACA, which insured the Abacus deal.

    RBS took $840 million in losses on the Abacus transaction.

    Goldman also admitted that its marketing materials for the deal "contained incomplete information," and that it "regrets" that it didn't fully disclose the role short-seller John Paulson played in selecting the investments. Paulson, who made billions betting on the collapse of the housing bubble, helped select investments in the deal.