UPDATE 4-Agrium raises bid for CF, but shares sell off

* Cash-and-stock bid is worth $92.99 per CF share

* CF shares plunge; Terra, Agrium shares up

* Agrium says this is its final offer (Adds CEO comments; All figures in U.S. dollars, unless noted)

By Euan Rocha and Michael Erman

TORONTO/NEW YORK, Nov 5 (Reuters) - Canada's Agrium Inc(AGU.TO) sweetened its hostile bid for U.S. fertilizer rival CF Industries Holdings Inc (CF.N) on Thursday, but the latest maneuver in a drawn-out three-way takeover battle failed to impress CF's investors, and CF shares fell about 8 percent.

Agrium has been pursuing a deal with CF since February, while CF has put in a hostile bid for U.S. rival Terra Industries Inc <TRA.N. Both Agrium and CF have sweetened their bids many times, while their targets have spurned all overtures.

"I don't think Agrium's latest offer is enough and I don't think CF is going to jump at this offer," said Morningstar analyst Ben Johnson. "The deadlock is going to continue, pending the outcome of the Terra shareholder meeting."

Terra on Wednesday rejected a sweetened bid from CF as inadequate. But CF has nominated a slate to Terra's board and a vote is scheduled for Nov. 20. A victory for the CF slate would likely help CF clinch a deal.[ID:nN04543202]

Share price moves on Thursday also suggest that investors are betting on improved prospects of a deal between CF and Terra.