The head of the Federal Communications Commission is revising proposed rules for regulating broadband Internet, including offering assurances that the agency won't allow companies to segregate Web traffic into fast and slow lanes.

The new language by FCC Chairman Tom Wheeler to be circulated as early as Monday is an attempt to address criticism of his proposal unveiled last month that would ban broadband providers from blocking or slowing down websites but allow them to strike deals in which content companies could pay them...