PrivateBancorp announced on Wednesday that it is postponing a special meeting for shareholders to vote on a US$4-billion takeover offer from CIBC. The move comes as Canada’s fifth-largest lender faces mounting calls to hike its bid amid a recent rally in U.S. regional bank stocks.

While the CIBC-PrivateBancorp deal was announced in June, the vote was scheduled to take place on Dec. 8.

CIBC remains committed to the deal “on the agreed terms, which were established by both companies based on our analysis of the fundamental, long-term merits of the combination,"  Victor Dodig, president and CEO of CIBC, said in a statement.

PrivateBancorp said a new date for the meeting is expected to be set in the first quarter of 2017.

“In view of the significant changes to trading market conditions over the past few weeks, we believe it is in the best interests of all of PrivateBancorp's stockholders to have additional time to consider the value and long-term strategic benefits of this transaction,” PrivateBancorp Chairman James Guyette said in a statement.

In the past week, two proxy advisory firms, including ISS and Egan Jones, have recommended shareholders vote against the CIBC-PrivateBancorp deal. Glass Lewis, another well-known proxy advisory firm, has also switched its view, arguing that investors would not be well-served by the agreement.

'NEGOTIATING STAGE'

Since CIBC announced the cash and stock deal to buy the Chicago-based bank in June, PrivateBancorp shares have soared about 30 per cent. The surge has occurred amid a rally among U.S. regional bank stocks in the wake of Donald Trump’s election victory.

PrivateBancorp shares closed at US$52.14 on Tuesday, far surpassing the US$47 bid value when the transaction was announced on June 29.

Peter Routledge, financial services analyst at National Bank Financial, said that PrivateBancorp and CIBC are back in a “negotiating stage.”

“In effect what the PVTB board has done in delaying the shareholder vote is saying, ‘Well, we want more,’ and CIBC has said ‘We don’t want to pay any more. We have an agreement in place,’” Routledge said on BNN on Wednesday. “The way I thought about it when it first came out, was that this was an expensive acquisition. Turns out, it was pretty well priced.”

CIBC's plan to use the PrivateBancorp acquisition to help boost its growth in the U.S. market "is a great strategy – but it just got a little bit more expensive to do so," Routldge said. 

The postponed vote increases the likelihood that CIBC will be forced to consider increasing its offer, according to Barclays analyst John Aiken.

"In our opinion, CIBC’s management will struggle between its desire to pursue its U.S. ambitions through this vehicle and maintaining the relative prudence of its original offer," Aiken wrote in a note released Wednesday. "While we do not anticipate a sweetened bid from CIBC, we do admit that the likelihood is far from remote."

When it announced the deal in June, CIBC said the PrivateBancorp acquisition would help it significantly expand its reach in North America. PrivateBancorp has about 1,200 employees and a presence in 12 U.S. markets.