Securities and Exchange Commission Chairman Mary Jo White unveiled a sweeping set of initiatives Thursday to address mounting concerns about the impact of computer-driven trading on the stock market, including proposals that would extend oversight of high-frequency traders and dark pools.

White said the agency will launch a new committee to weigh proposed SEC initiatives and rule changes about how the stock market functions. The SEC will also review key market regulations and exchange practices such as the use of complex order types that can give certain investors an advantage, she said.