Investment Technology Group, a New York-based brokerage and technology firm, is weighing a bid for a trading system being sold off as part of the streamlining of the New York Stock Exchange by its new owner, according to people familiar with the situation.

Under the deal being considered, ITG would buy Nyfix from IntercontinentalExchange Group to bolster its networking business, the people said. Robert Gasser, president and chief executive of ITG, was the CEO of Nyfix from 2001 until 2006.