He also dismissed as unlikely the recent predictions by Gerry Robinson, chairman of Granada Group, which is buying Yorkshire-Tyne Tees Television, that all the ITV stations would merge within a decade.
Speaking at an Institute of Economic Affairs Conference on the future of UK broadcasting, Mr Smith said four big owners - Carlton Communications, Granada, United News & Media and Scottish Media Group - would emerge. He added: "In the course of the next few months, we will see the establishment of three major blocks of ITV channels in England and Wales and one in Scotland."
He said he was "relaxed" about the rapid consolidation of ITV into the hands of four main players, but warned that the regional character and programming of each ITV franchise must not be sacrificed in the rush to rationalise.
"It's extremely important that as the regions of ITV come together we do ensure that the regional character of the stations and the programme making is maintained. We do not want to see the regional definition disappearing as more and more gets concentrated in the hands of fewer and fewer," he added.
His comments come at a time of frenetic takeover activity in the industry. Within the space of a month, Scottish has bought Grampian Television; Granada has tabled an agreed bid for Yorkshire-Tyne Tees; and United has made a recommended offer for HTV Group.
The 15 ITV franchises were awarded to 14 separate holding companies in 1993. If, as seems likely, the two most recent offers go through, only three small independent companies will remain - Border Television, Ulster Television, and Channel Islands Communications.
The Heritage Secretary also yesterday alluded to plans for the creation of Ofcom, a regulatory body to cover the converging media and telecommunications industry.
Mr Smith said laying a new regulatory framework would take at least two years and would follow widespread consultation.
Referring to public disagreements between the Independent Television Commission and Oftel on BSkyB's involvement in British Digital Broadcasting, he said he had "observed a slight nuance of difference" between the two watchdogs. He warned that Oftel and the ITC must co-operate on the regulation of digital television until a new framework could be established.
"We will make sure the current regulators work properly together in accordance with their remits," he said.
He said his department was working in conjunction with the Department of Trade and Industry to consider how Ofcom should be developed.
Mr Smith also indicated yesterday that Channel 4's remit should be redefined to ensure the broadcaster's distinctiveness, its provision for minority interests and its "ability to be less mainstream".
Under the terms of the 1990 Broadcasting Act, Channel 4 is obliged to screen a suitable proportion of programming not generally catered for by Channel 3. This definition is likely to be honed in a new broadcasting bill.
However, Mr Smith has already indicated that there will be no new media legislation in this session of Parliament, which runs until October 1998.