ZURICH (Reuters) - Lonza said on Thursday it has struck a deal to sell its water care business to U.S. investment company Platinum Equity for $630 million (£489 million).

Lonza, which said it was selling the business as part of its long-term strategy to focus on its health care business, expects the deal to close in the first quarter of 2019. The inclusion of the French business in this transaction is still under discussion.

The water treatment and residential swimming pool care business has six manufacturing facilities, including North America, South America, Europe and South Africa, with roughly 1,200 employees.

Lonza said in May that it had taken on an investment bank to look at strategic options for the business that sells HTH brand swimming pool products.

Lonza, a chemicals and drug ingredients maker has been increasing its presence in the health care business, buying pill capsule maker Capsugel for $5.5 billion in 2016.

That deal was designed to expand its range of services beyond drug ingredient and production services the Basel company has traditionally supplied.

"We are putting the Water Care business in the hands of an experienced owner who will develop Water Care as a stand-alone business while focusing on innovation and further growth," Lonza Chief Executive Richard Ridinger said.

"The divestment further strengthens our strategic focus on our three core pillars – Pharma & Biotech, Consumer Health and Consumer & Resources Protection – within the healthcare continuum."

(Reporting by John Revill; Editing by Maria Sheahan)