By Will Feuer

Shares trading in Toronto rose midday Thursday as traders continued to digest data about the spread of the Omicron variant of the coronavirus and how effective currently available vaccines are against the new variant. Shares in Canadian National Railway Co. rose in midday trading as activist investor TCI Fund Management Ltd. called on the company to delay picking its next CEO until after the special shareholder meeting in March.

Canada's S&P/TSX Composite Index rose 0.74% to 21,226.56 while the blue-chip S&P/TSX 60 climbed 0.78% to 1,289.15.

Canadian National shares were 1.21% higher at midday. TCI said Canadian National's "board is conflicted, which makes the current selection process flawed and unreliable." TCI has nominated four independent candidates to Canadian National's board and urged shareholders to vote for them at the special meeting in March.

The appointment of Canadian National's new CEO should wait until after that meeting, TCI said. The statement comes after Canadian National said earlier this week that it expects to name a new CEO in January after former Canadian National employee Jim Vena withdrew his name from consideration.

Representatives for Canadian National did not immediately return a request for comment.

Other market movers:

Shares of Curaleaf Holdings Inc. rose 3.72% in midday trading after the company said it struck a cash-and-stock deal to acquire a dispensary in Safford, Ariz., for $13 million. Upon closing the deal, Curaleaf said it intends to relocate the store to a new, 9,000-square-foot flagship dispensary in Scottsdale, Ariz.

Write to Will Feuer at Will.Feuer@wsj.com

(END) Dow Jones Newswires

12-23-21 1252ET