The Canadian Imperial Bank of Commerce has sweetened its bid to acquire Chicago-based PrivateBancorp Inc. for the second time, adding an additional US$3 in cash for each share of common stock held.

The amended agreement released on Thursday — roughly one week before PrivateBancorp shareholders were due to vote on CIBC’s already sweetened offer — values the U.S. bank at approximately US$4.9 billion or $6.8 billion based on Wednesday’s closing price for CIBC’s common shares on the New York Stock Exchange of US$79.58.

That represents a 26 per cent increase in value compared to the initial terms announced in June 2016, the companies said.

“CIBC affirmed that the terms of the Amended Agreement represent CIBC’s best and final offer to the PrivateBancorp stockholders,” the banks said in a joint release on Thursday.

PrivateBancorp’s board of directors unanimously recommended that stockholders vote in favour of the merger, the companies said.

Shareholders were already scheduled on May 12 to vote on CIBC’s revised offer announced in March.

CIBC had already upped its bid for PrivateBancorp Inc. on March 30, offering another 20 per cent on top of its initial offer made on June 29, 2016 to reflect soaring valuations of U.S. bank stocks in the wake of Donald Trump’s election.

This added US$3 — which in the aggregate will be equal to $27.20 in cash and 0.4176 of a CIBC common share for each share of common stock of PrivateBancorp held — announced Thursday is a “last push to get the deal over the line,” said John Aiken, an analyst with Barclays in Toronto.

“We believe that this does materially increase the likelihood of success, particularly with the added benefit of potentially delaying its quarterly dividend payment to ensure that PVTB shareholders receive their first CIBC dividend right off the bat,” he said in a note to clients.

“While we do believe that CIBC has been an unfortunate victim of circumstances, as it points out, this second amendment now represents an incremental 26 per cent in cost over the initial bid. We have to question how much of the bank’s initial conservatism in its assumptions, including eventually higher rates, has now been eroded with the two step ups in the bid required to ensure success.”

The Canadian lender’s offer in March of US$24.20 in cash and 0.4176 of a CIBC common share for each share of common stock of PrivateBancorp held, valued the U.S. bank at approximately US$4.9 billion or $6.6 billion. That’s compared to the US$3.8 billion or $4.9 billion valuation in June when the deal was first announced.

However, Thursday’s revised offer still values PrivateBancorp at US$4.9 billion, but the Canadian currency equivalent has risen to $6.8 billion.

The loonie has fallen 2.95 per cent between March 29 and May 3, from US75.04 cents to US72.83 cents.

As well, the value of CIBC’s stock in New York has fallen by 9.5 per cent since it announced its revised offer in March.

On March 29, CIBC shares in New York were US$87.92. On Wednesday, shares of the Canadian lender closed in New York at US$79.58.

“The increase in the cash portion of the deal essentially makes up for the impact from the recent decline in CIBC shares,” said Brian Klock, an analyst with Keefe, Bruyette and Woods Research. “Accordingly, the overall $4.9 billion price tag for the deal is relatively unchanged.”

If successful, the acquisition of PrivateBancorp would mark CIBC’s largest ever. The Canadian lender has the smallest international footprint among its peers, and this foray into the U.S. market would give CIBC exposure to expected growth and rising interest rates south of the border while the economy at home slows.