Dec 17 (Reuters) - Johnson Matthey (JMAT.L) said on Friday it will sell its health business to investment firm Altaris Capital Partners for an enterprise value of about 325 million pounds ($432.71 million), as the chemicals maker plans to refocus on its core assets. The London-listed company said it would retain a 30% stake in the health business, which develops and manufactures specialist and complex active pharmaceutical ingredients. Johnson Matthey, which began a review of the division eight months ago, said it would take an impairment hit of 200 million pounds from the sale expected to close by mid-2022. The news comes after the firm announced last month that it was selling its battery materials and glass technologies businesses, while it brings in Bayer AG"s (BAYGn.DE) Liam Condon as its new boss in March. The British company, which makes car pollution filters and plans to focus on areas such as hydrogen technologies, said it would redeploy about 150 million pounds of capital expenditure previously earmarked for the non-core health division to higher growth businesses. ($1 = 0.7511 pounds)