Underwriting agency PI Direct has not ruled out using additional capacity providers beyond its current backers, the company said.
PI Direct chief executive Michael Wood said it was "not impossible we could share capacity around" in the future.
But he added the group would stick with current backers "at present".
The group's external capacity is currently provided by Hiscox and Catlin.
PI Direct also owns mutual insurer Magian Mutual, which underwrites professional indemnity insurance for IFAs.
Wood said: "We are always considering getting additional capacity from outside our mutual.
"But we need to consider member interests."
The group's gross written premium is about £55m.
Online quote system launched
PI Direct is set to its expand its direct sales presence with the launch of an online quote system.
Chief executive Michael Wood said the quote engine would be targeted at small professional firms - although not solicitors and IFAs - with fee incomes of up to £250,000.
Wood said he anticipated the amount of business written through the system to be "less than £5m".
He added that the size of the group's book of business in this sector was only £10m.