DUBAI, Feb 1 (Reuters) - Saudi Telecom Co 7010.SE (STC) will buy a further 25.8 percent of Viva VIVA.KW for 1.59 billion riyals ($424.00 million), taking majority control of its affiliate following the close of a voluntary tender offer period for the Kuwaiti firm's shares.

This will raise STC's stake in Viva to 51.8 percent, the Saudi firm said in a bourse statement on Monday. The former monopoly currently owns 26 percent of Viva, which rapidly won market share after launching services in 2008 and turned profitable four years later. urn:newsml:reuters.com:*:nL8N1430F8

STC in December said it would offer 1 dinar ($3.30) per share for all shares in Viva it did not own, a proposal Viva's board described as unfair. urn:newsml:reuters.com:*:nL8N14B0A0

Viva's shares had hit a record high of 1.1 dinars before STC revealed its offer price, but Gulf stock markets have since slid following a renewed slump in oil prices. Viva's shares ended Sunday at 0.940 dinars.

Kuwaiti state institutions own about 16 percent of Viva, Reuters data shows.

($1 = 0.3031 Kuwaiti dinars)

($1 = 3.7500 riyals)

(Reporting by Matt Smith; Editing by David French) ((matt.smith1@thomsonreuters.com; 00971506354039; Reuters Messaging: matt.smith1.thomsonreuters.com@reuters.net))

Keywords: VIVA M&A/SAUDI TELECOM