Nasdaq OMX Group plans to offer a third U.S. equity trading platform during the second half of 2010, pending SEC approval, the exchange operator announced today.

Nasdaq OMX's new trading platform will offer a new price/size priority model using the license acquired from its 2007 acquisition of the former Philadelphia Stock Exchange, known today as Nasdaq OMX PHLX.

Nasdaq OMX's new equity price/size priority market structure is not offered on the Nasdaq Stock Market, Nasdaq OMX BX or any other U.S. equity- trading platform, according to the release. The new model gives cutomers the ability to choose how to execute orders by either selecting a price/size priority model on Nasdaq OMX PHLX or a price/time priority model available on the exchange's other two U.S. equity trading platforms.

Nasdaq's new equity platform will also run on the INET technology to leverage the speed and efficiency benefits offered throughout Nasdaq OMX globally.

In a statement, Erick Noll, EVP, Nasdaq OMX Group, said the exchange was "Continuing a tradition of offering customers additional choices that will help supplement their various trading strategies. Based on feedback from key customers we decided o announce the launch of his trading platform that offers a new competitive equity market structure model," stated Noll. He pointed out that this would extend "the many assets of our acquisition of the Philadelphia Stock Exchange, yet again, to provide the benefits to our equity trading customers."

Currently, Nasdaq Stock Market and Nasdaq OMX BX offer customers a price-time priority model with different pricing and functionality. Nasdaq OMX will reactivate its Nasdaq OMX PHLX equity license to offer the price/size priority model.