It has clarified it will not have a statutory role in assessing mergers unless asked to do so by the Department of Trade and Industry and will use a panel of newspaper industry experts for advice.
Ofcom's initial consultation document on a "public interest test" for newspaper and broadcast media mergers had led to concerns that it would have too much power.
The first test of Ofcom's powers in this area is likely to be the Telegraph Group takeover, if Ofcom is called on to investigate it by the DTI.
Ofcom has clarified other points on its role in media mergers. It said it will not be involved in the DTI's decision to issue an intervention notice.
During the consultation period, News International expressed concerns that the role Ofcom had in mergers would increase red tape and its powers would extend beyond advising on mergers.
Stephen Carter, the Ofcom chief executive, said: "This has been an intensive and informative consultation. The guidance on this specific role for Ofcom is clearer and hopefully more useful for prospective buyers and sellers."