Heads of both AT&T and Time Warner have, however, rebuffed claims that their deal might get blocked.
The merger, believed to be the biggest in the world this year, is subject to regulatory approval.
The deal where AT&T is valuing Time Warner at $110 per share could be announced as early as Sunday.
This will be launched in summer in selected areas north of London, before a wider roll-out later in 2016.
BlackBerry Priv Android phone will be available for $24.99 (£16.20) with a new two-year contract on AT&T.
The two companies control about 80% of US's "special access network", the telephone and broadband lines used to carry data.