CCGs that choose to merge and federate with other CCGs will not concern Monitor, it is claimed.
Dr David Bennett, Monitor Chair and Interim Chief Executive, said the regulator's primary focus will be concentrating on CCG behaviour and not its size or position.
"It is absolutely not the case that just because [a CCG] gets into a position of some dominance, that it automatically means we will be worried about it," he said.
"What matters is what the CCG is doing with that position."
Sharon Lamb, a Partner at Capsticks law firm, gave further reassurance to CCGs.
"While competition law will apply to GPs as providers, the legislation is unlikely to apply to CCGs in terms of mergers because they are not behaving as businesses in the market," she said.
Speaking to GP Business at last month's NHS Clinical Commissioner's conference, Crawley CCG Chair Dr Amit Bhargava warned Monitor's involvement in the reformed NHS could put CCGs off working together.
"CCG partnerships may highlight the role of general practice as providers of care," he said.
"CCGs must ensure they collaborate and not be seen to be colluding. The transparency of decision making is key to ensuring this."
Dr Bennett said Monitor and the NHS Commissioning Board needs to provide either separate or joint guidance to help CCGs understand "what they can and can' do".
However, he said much of what CCGs are worried about in terms of commissioning regulations is "already here today and is inescapable".