CVC to buy health firm Capio's Spain unit -sources

* 900 mln euro deal to close later in January -source

* CVC regaining business it sold to Capio in 2005

By Quentin Webb and Simon Meads

LONDON, Jan 6 (Reuters) - CVC has agreed to buy Spain's biggest private healthcare firm from Capio, the European hospital group owned by rival buyout firms Apax and Nordic Capital, people familiar with the matter said on Thursday.

The sale of the Capio Sanidad unit is likely to close later this month, following regulatory approvals, and will give the unit an enterprise value of about 900 million euros ($1.2 billion), one of the people said.

CVC is regaining a business it exited six years ago. In 2005 it sold the unit, then known as IDC Grupo Sanitario, to Gothenburg, Sweden-based Capio AB, then a public company, for 330 million euros. A year later Nordic and Apax took the parent company private in a $3.3 billion leveraged buyout.

Apax [APAX.UL], CVC [CVC.UL] and Nordic declined to comment. Capio officials did not immediately respond to requests for comment. ($1=.7609 Euro) (Reporting by Quentin Webb and Simon Meads; additional reporting by Andres Gonzalez in Madrid; editing by Douwe Miedema)