Roche Holding AG (ROG.VX) is likely to succeed in fully taking over U.S. biotech company Genentech Inc. (DNA) after raising its offer price for the 44% of shares it doesn't already own in the U.S. biotechnology company, analysts said Monday.

Seeking to conclude an eight-months battle to gain full control of Genentech, Roche on Friday increased its bid 7.5% to $93 a share and extended its tender offer to shareholders until March 20. The new offer values the deal at $45.7 billion.

"The raised offer significantly increases the likelihood of a successful tender, while still preserving the assertiveness of the transaction for Roche," said David Kaegi, pharmaceutical analyst in Zurich with private bank Sarasin, who has a buy rating on the stock.

Roche shares benefited from the market's newly-found belief in the takeover's success. At 1215 GMT, Roche shares were up CHF3.20, or 2.5%, at CHF132, while the Swiss market overall was lower.

Genentech's Special Committee of independent directors again rejected Roche's offer as too low, but the chances that Roche will succeed have vastly increased with the new offer, many analysts said.

"Roche has held a series of meetings with shareholders of Genentech in New York last week and the revised offer price may reflect the feedback gathered during these meetings," said Karl-Heinz Koch, pharmaceutical analyst in Zurich with independent broker Helvea, who has a buy rating on the stock.

Roche, based in Basel, Switzerland, has raised around $36 billion at a cost of less than 5% through a series of bond issues in major currencies. Together with the roughly $7 billion in liquid funds that the drugmaker has on its balance sheet, it commands more than $43 billion in cash to finance the transaction, Koch estimates.

Roche has said it would proceed with the offer only if more than half of the minority shareholders tender their shares by the new deadline.

"The higher offering now increases the downside risk for Genentech shareholders should the Avastin adjuvant colorectal data be negative," Sarasin's Kaegi said.

An interim analysis of the data is expected next month. If the study proves that Avastin, a top-selling cancer drug, works in early stages of cancer, the drug's potential sales would skyrocket, analysts say. A successful outcome of the study would also support the valuation of Genentech, though Roche has said the benefit of controlling Genentech aren't hinging on a successful outcome of the study.

Company Web Site: http://www.roche.com

-By Anita Greil, Dow Jones Newswires; +41 43 443 8044 ; anita.greil@dowjones.com