US stocks rallied in late trade but gains were limited as Boeing and Facebook shares took a hit.
The Wall Street Journal reported the Federal Aviation Administration's approval of the aircraft is being investigated by the inspector-general of the US Transportation Department. The social media giant has come under further pressure after a gunman live streamed a massacre of Muslims in Christchurch in New Zealand on Facebook.
Mrs May is expected to seek an extension to the Brexit deadline ahead of this week's European Union summit."It now looks like the Parliament will not be voting again ahead of the EU meeting on Thursday," he wrote in a note.