Swiss drugmaker Roche Holding AG has secured more than 96 percent of shares in Genentech Inc , effectively completing its $46.8 billion buyout of the U.S. biotech group.

Roche said on Thursday it now holds some 93 percent of outstanding Genentech shares, a further 3 percent are guaranteed to be delivered within the next three business days and it will integrate the U.S. biotech group as soon as possible.

The Swiss group agreed earlier this month to acquire the 44 percent of shares in the U.S. firm it does not already own for $95 each, ending a long pursuit of the U.S. biotech group and its lucrative cancer drugs.

Roche said remaining holders of Genentech shares would revive $95 a share.

It will make Genentech a wholly owned subsidiary as soon as possible and, following the merger, the U.S. company's stock will no longer be traded on the New York Stock Exchange.

Roche's Genentech buy is the third big acquisition by a drugmaker this year, following Pfizer Inc's
$68 billion acquisition of Wyeth and Merck & Co Inc's $41 billion tie-up with Schering Plough Corp .

The deal underlines big pharmaceutical companies' drive to secure promising new medicines as the flow of traditional drugs from research labs stalls and patents on current billion-dollar sellers expire.

(Reporting by Lisa Jucca and Sam Cage; editing by Simon Jessop)