SOUTH SAN FRANCISCO, Calif., Aug. 14 (UPI) -- Swiss pharmaceutical behemoth Roche will have to dig deeper into its pockets if it wants to own all of Genentech Inc. (NYSE:DNA), which rejected its $43.7 billion offer.

Analysts said that's exactly what they expect Roche to do after the South San Francisco company turned down its $89-a-share tender Wednesday, The New York Times reported.

One analyst, Mark Schoenebaum of Deutsche Bank, advised his clients that Genentech's tone in rejecting the offer "appears friendly." That, he said, indicates there will be negotiations and "consummation of a deal continues to seem likely."

Genentech's shares closed the day at $98.37 and some analysts now think Roche, which owns just under 56 percent of Genentech, may have to pay in the $100-$105 range, the Times reported. However, a Roche spokeswoman said the company still thinks its initial offer is "fair and generous."