LONDON, Nov 16 (Reuters) - A major Canadian pension fund is likely to buy out Britain's Burton's Biscuits, the makers of popular treats Jammie Dodgers and Wagon Wheels, Sky News reported on its website on Saturday, citing unnamed sources.

Ontario Teachers' Pension Plan is finalising the 350 million-pound deal which is expected this weekend, although sources close to the talks told Sky that it was possible another bidder could make an improved last-minute offer.

The Canadian pension fund - which manages assets worth C$127.3 billion (75.6 billion pounds)- has bought several British companies in recent years, acquiring the nursery chain Busy Bees in October and National Lottery operator Camelot.

Warburg Pincus, Clayton Dubilier & Rice and Apax Partners all put in rival bids on Thursday for Burton's Biscuits which also produces Maryland cookies and Cadbury biscuits.

If the deal goes through, it could well act as a forerunner to a potential offer by the Canadian fund for the much larger United Biscuits, bought by two private equity firms for 1.6 billion pounds in 2006, which encompasses brands McVitie's, Jaffa Cakes and Jacob's.

Neither Burton's Biscuits nor the Ontario Teachers' Pension Plan were immediately available for comment when contacted by Reuters.