UPDATE 1-RioCan REIT to raise C$124.5 mln via public offering

* To sell about 6 mln trust units at C$20.75

* Issue at 1 pct discount to Monday's close

* To use proceeds mainly for acquisitions

Aug 30 (Reuters) - Canada's RioCan Real Estate Investment Trust (REI_u.TO) said it would raise C$124.5 million in a public offering of trust units to mainly fund acquisitions.

Canada's biggest and oldest real estate investment trust said it would offer 6 million trust units for C$20.75 apiece. The sale represents a 1 percent discount to the stock's Monday's close.

RioCan also granted its syndicate of underwriters, co-led by RBC Capital Markets, TD Securities Inc and BMO Capital Markets, an option to buy an additional 1.2 million units at the same price, the company said in a statement.

The offering is expected to close on or about Sept 8., it added.

Earlier this month, Toronto, Ontario-based RioCan had said it was considering buying a number of properties in Canada and in the U.S. market, which it entered recently.[ID:nN11238433]

Shares of the Trust closed at C$21 Monday on the Toronto Stock Exchange. (Reporting by Arnika Thakur in Bangalore; Editing by Vyas Mohan)