Ashland Inc. agreed to sell its water technologies unit to private-equity firm Clayton Dubilier & Rice LLC in a deal valued at about $1.8 billion.

The acquisition should close by Sept. 30, Covington, Kentucky-based Ashland said today in a statement. Net proceeds of about $1.4 billion from the asset sale mostly will be used for share repurchases, Ashland said. It authorized $1.35 billion of stock buybacks, replacing a program with $450 million remaining.

Ashland said in November it would exit the water-chemicals business as part of an overhaul that includes selling its elastomers unit, which supplies synthetic rubber to tire makers. Ashland is focusing on expanding in additives used in cosmetics and pharmaceuticals after its $3.2 billion purchase of International Specialty Products Inc. in 2011.

Clayton Dubilier was one of three bidders for the Ashland unit as of a Feb. 10 deadline, people familiar with the matter said last week. Blackstone Group LP and Rhone Group LLC also made offers, the people said.

Ashland rose 1.2 percent to $97.29 at 9:51 a.m. The shares are little changed this year.

Financial services industry