ITV is planning cutbacks for dramas such as London's Burning, Heartbeat and Peak Practice to make room for new commissions.
Nick Elloitt, ITV Drama Controller, said: "I don't think we will be cancelling any shows, but some of them probably need a bit of freshening up.
"This could be done with shorter runs, or introducing new elements to make them more attractive, more marketable. Having shorter runs will also create more space for new shows.
"The temptation is to just cancel long running shows. But if you do that you can spend years trying to find replacements that achieve the same viewing figures."
One new drama planned by the network is Manchester Stan from Granada, starring John Thompson.
"John plays a character like Arthur Daley, a would-be dodgy dealer," Elliott said. "The comedy comes from the fact that he's usually bested. He's not very good at being a spiv type."
More new 60-minute dramas are expected to be announced later this year.
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