The Competition and Markets Authority is to investigate the merger between platform Nucleus and SIPP provider Curtis Banks.

The CMA announced today it would review the planned £242m merger of Nucleus and SIPP and SSAS firm Curtis Banks.

The move effectively puts the merger on hold until the CMA makes its decision.

The merger inquiry was launched today to ascertain whether the combination of the two firms could damage competition in the sectors they operate in.

It is understood that Nucleus referred itself to the CMA as part of the acquisition process, although the CMA has only announced an inquiry today.

A spokesperson for Nucleus told Financial Planning Today: "We remain excited about our proposed acquisition of Curtis Banks and welcome today's update from the CMA. We continue to collaboratively engage with the regulators as the conditions of the transaction are processed."

It is understood that Nucleus is still aiming for the merger to be completed by Q3 depending on the outcome of the inquiry. It will also require regulatory approval for the deal.

The CMA's initial invitation to comment on the merger will run from today until 2 August. The deadline for a decision on phase 1 of the inquiry will be 14 September.

In a statement today the CMA said: "The CMA is considering whether it is or may be the case that this transaction, if carried into effect, will result in the creation of a relevant merger situation under the merger provisions of the Enterprise Act 2002 and, if so, whether the creation of that situation may be expected to result in a substantial lessening of competition within any market or markets in the United Kingdom for goods or services."

The CMA is inviting comments from any interested party.

The CMA is launching the review under Section 96(2A) of the Enterprise Act 2002.