Financial terms and conditions of the deal have not been disclosed by both parties.

KDC will be re-branded as the ‘Cowen Equity Finance Group’ and will operate from New York on completion of the transaction.

The current head of KDC’s securities lending business Rory Zirpolo will join as managing director and head of the Equity Finance Group and report to Cowen’s co-heads of equities, Tom O’Mara and Dan Charney.

Commenting on the deal, Cowen and Company chief executive officer Jeff Solomon said KDC Securities was launched seven years ago, and since then Kellner and its securities lending team have contributed to the equity finance platform.

"We believe the business is well positioned for future growth and is a strong complement to our existing sales and trading footprint," Solomon added.

The deal is expected to close during the fourth quarter of 2012, after obtaining the regulatory approvals and satisfying certain closing conditions.

Cowen together with its consolidated subsidiaries offers alternative investment management, investment banking, research, and sales and trading services.