TORONTO -- The downturn in Alberta has taken a bite out of sales growth at Pizza Pizza Royalty Corp. (TSX:PZA).

The Toronto-based company says sales at its Pizza 73 locations in Alberta were down, partly offsetting gains at its main banner -- primarily in Ontario.

Same-store sales -- those at restaurants open for at least a year -- grew by 3.4 per cent overall. Pizza Pizza's same-store sales were up 5.3 per cent and Pizza 73's were down 5.3 per cent in the fourth quarter of 2015 compared with a year earlier.

The figures were included with Pizza Pizza's financial report for the quarter and year ended Dec. 31.

Total system sales from all restaurants grew by 5.6 per cent to $533.8 million in 2015, up from $505.4 million in 2014. Fourth-quarter system sales grew by 4.4 per cent to $141.4 million in the fourth quarter from $135.5 million.

Royalty income for Pizza Pizza Royalty Corp. was $34.8 million for the year, including $9.2 million in the fourth quarter. That compared with $33 million in 2014, including $8.7 million in its fourth quarter.

Earnings for the quarter rose to $6.9 million from $6.7 million. Earnings for the year increased to $25.2 million from $25.0 million in 2014.

Fourth-quarter earnings grew to 22.5 cents per share from 22.2 cents, while full-year earnings per share fell to 82.1 cents from 82.6 cents. Adjusted earnings per share for the quarter was 23.3 cents, up from 23.1 cents, while adjusted earnings per share for the year rose to 89.5 cents per share from 86.1 cents in 2014.