TORONTO, Jan 6 (Reuters) - Canada's top health official Theresa Tam has warned that COVID-19 cases in the country could jump in coming days, due to community spread of the Omicron variant.

Concerns over the highly transmissible variant have spooked investors around the world and prompted companies to delay return-to-office plans.

Here are updated plans of Canadian banks and insurers to bring staff back to office:

Royal Bank of Canada: Canada's biggest bank by market value has told staff to work from home in regions where provincial governments have advised employers to maintain remote work where jobs allow.

The bank had not announced a firm return-to-office date and had encouraged employees to work from home until the new year.

Bank of Nova Scotia: Scotiabank has paused plans to begin a phased return for its Toronto head-office employees from Jan. 17. When the return happens, it will be staggered for different groups and most head-office staff will follow a hybrid working model.

Sun Life Financial Inc: Canada's second-biggest life insurer has paused its office re-opening pilot for more employees until the end of January.

The company has launched a flexible return-to-office approach for a majority of its 12,000 staffers in Canada, that will allow them to choose where to work from.

National Bank of Canada: Canada's sixth-biggest lender has asked employees to work remotely if possible.

Toronto-Dominion Bank: The bank asked employees who are able to do so to work from home until further notice.

Bank of Montreal: Canada's fourth-largest bank has asked its investment bankers to go back to working from home until the week of Jan. 17, according to a Bloomberg News report https://www.bloomberg.com/news/articles/2021-12-16/bank-of-montreal-asks-investment-bankers-to-work-from-home?sref=vEQJzSks.

Canadian Imperial Bank of Commerce: Canada's fifth-largest lender has asked its staff in the country to work remotely and halted plans for a return to work location in January.

Manulife Financial: Canada's biggest life insurer has paused its return-to-office date for employees in North America, according to a memo seen by Reuters. Earlier, it had planned Jan. 24 for return to office for U.S. workers.

The banks and insurers also have mandatory vaccination policies https://www.reuters.com/world/americas/canadas-major-banks-require-employees-entering-premises-be-vaccinated-2021-08-20 that employees must follow to return to their premises. (Reporting by Nichola Saminather, Niket Nishant, Manya Saini and Sohini Podder; Editing by Marguerita Choy, Barbara Lewis, Ramakrishnan M., Anil D'Silva and David Gregorio)