With just a few hours until deadline, it would appear that ICN Pharmaceuticals ( ICN) will complete its acquisition of Ribapharm ( RNA) in a deal that has been as contentious as it is unusual.

Shareholders of Ribapharm have until 5 p.m. EDT to tender shares to ICN for $6.25 per share in cash, an increase from ICN's original cash tender bid of $5.60 announced in June. The offer is for the approximately 20% of Ribapharm shares that ICN doesn't already own.

Neither company would discuss the progress of the cash tender offer; but judging from trading in Ribapharm's stock, it would take a dramatic last-minute surprise for the transaction to fail.

Since ICN raised its offer on Aug. 4, Ribapharm's stock has barely budged, with closing prices hovering between $6.14 and $6.17 a share. In midday trading Tuesday, the stock was at $6.18.

The higher price came with a caveat: Ribapharm agreed to drop a poison pill, originally designed to kick in if a suitor acquired more than 89.9% of its shares.

In return, Ribapharm, whose board still calls ICN's offer "inadequate," agreed to let the deal go through if two-thirds of Ribapharm's shareholders accepted the improved offer. When ICN raised its buyout offer, it said 53% of Ribapharm shareholders had accepted the cash tender offer at the original price.

ICN and Ribapharm are both based in Costa Mesa, Calif. ICN spun off Ribapharm in April 2002 while retaining about 83% of the spinoff's shares. ICN originally said it would distribute the rest of the shares to Ribapharm shareholders within six months of the IPO. The IPO price was $10 a share.

All of Ribapharm's revenue comes from royalties from the drug ribavirin that it licenses to Schering-Plough and Hoffmann La Roche. ICN's sales reflect a mixture of ribavirin royalties as well as many other drugs.

ICN also reported last week that it had reached an agreement in principle to settle six lawsuits filed by Ribapharm shareholders who alleged ICN had "breached its fiduciary duties" as the controlling shareholder in Ribapharm relating to the original cash tender offer. No details were given for the agreement that was reached Aug. 4. A seventh lawsuit is still pending; all of the cases were filed in the Delaware Court of Chancery. A similar lawsuit is pending in California.