Channel Four has a host of popular shows
RTL, the German firm which owns channel Five, is contemplating a takeover bid for Channel 4, a report suggests.
It has asked investment bank JP MorganChase to examine the prospect of the move, The Sunday Times reports.
RTL has not commented on the report. A proposed merger between the two fell apart in 2004.
State-owned Channel 4 is suffering from a funding gap as advertising revenue falls and has warned it will run out of money by 2012.
Regulator Ofcom has estimated that Channel 4 may need up to £100m of extra funding to deliver its existing remit.
This has led the watchdog to consider funding options, including handing it some of the BBC's licence fee.
RTL, which owns more than 40 TV channels in 10 countries, has made no secret of its ambitions to expand its UK reach, and has previously been linked with a bid for ITV.