Martingale Asset Management bought itself back from parent company Commerzbank AG. Terms of the deal were not disclosed. Twelve partners will be majority owners of the firm, including Chairman Alan Strassman, CEO Arnold Wood and CIO William Jacques. The transaction is expected to close in late August. Martingale, a value-oriented quantitative shop with about $1 billion in assets under management, will retain its management structure and portfolio management teams and philosophies, Mr. Strassman said. Peter Pietsch, Commerzbank spokesman, confirmed the deal and had no further comment.