Oct 8 (Reuters) - Britain's Royal Mail said on Friday its GLS parcel service would buy Rosenau Transport for C$360 million ($286.8 million) as the postal company looks to bolster its freight carrier services in Canada.

GLS, which entered Canada three years ago by acquiring parcel delivery firm Dicom, will finance the deal using existing cash and loans, Royal Mail said.

The purchase will give GLS a network "stretching across the country" and add to its earnings and cash flow for the year ending March 2022, Royal Mail said.

"Rosenau Transport's model is similar to our existing Canadian business and provides an excellent fit," GLS Chief Executive Officer Martin Seidenberg said in a statement.

Rosenau Transport generated revenue of C$175.0 million and core earnings of C$41.6 million in the 12 months ended Aug. 31, with a mid-teens percentage operating profit margin.

Royal Mail, one of the world's oldest postal firms, gave an upbeat profit forecast last month as it benefits from improving letter volumes and higher UK parcel revenues as people shop online.

($1 = 1.2553 Canadian dollars) (Reporting by Sachin Ravikumar in Bengaluru; Editing by Ramakrishnan M.)