Basel, Switzerland  - Roche, the Swiss drug manufacturer, has struck a deal to buy out Genentech, a United States based biotech group, the two companies announced Thursday.

The move would cost Roche approximately 46.8 billion dollars for the 44-per-cent stake it does not already have in the biotech firm.

Under the agreement, the Swiss group would pay 95 dollars a share. It was only reached after months of negotiations, which at one point led Roche to go directly to shareholders with an offer that Genentech urged them not accept. Analysts felt the San Francisco company was holding out for a better price, as it was insisting on 112 dollars a share, far above market value.

The hostile takeover attempt appeared to have failed and Roche eventually upped the offer.

In a statement, Genentech said it urged its shareholders to sell to Roche.

If the deal goes through, the combined firm would be the seventh largest US pharmaceuticals company in terms of market share.

Roche has been selling bonds to finance the deal. (dpa)