I think that the answer varies across countries and industries as it depends on the level of expertise and experience of the in-house team. I think it would be crucial to engage an external due diligence adviser to perform financial and commercial due diligence in default as an independent opinion on the financial standpoint and valuation of the target company are crucial in the acquisition exercise. Other areas could be perform by the in-house team if the team possessed sufficient expertise and experience. The size of the acquisition could be another factor as large acquisition requires additional time, effort and resources. Engaging an experienced external adviser to assist the acquirer in the acquisition process would be meaningful as it would not be efficient for the acquirer to deploy its internal resources given that a large acquisition process are time consuming in nature.
