(Reuters) - Britain's Domino's Pizza Group (>> Domino's Pizza Group PLC.) said on Tuesday its annual pretax profit would be slightly ahead of market expectations after popular television music competition X Factor boosted its fourth-quarter sales.

The UK's biggest pizza delivery firm said more people ordered food at home since X Factor Final, the televised music competition, hit TV screens on Dec. 2, helping it post an 18.2 percent rise in fourth-quarter sales.

Domino's, which has most of its 1,192 stores in the UK but also operates in Ireland, Switzerland and Germany, said group system sales for the 13 weeks to Dec. 24 rose to 321.8 million pounds ($451 million) from 272.4 million pounds a year ago.

Sales at UK stores open over a year rose 6.1 percent during the 13-week period.

The London-listed company, a master franchisee of U.S. group Domino's Pizza Inc (>> Domino's Pizza, Inc.), said UK online sales rose 14.5 percent year-on-year in the fourth quarter, representing 77 percent of total system sales in the period.

(Reporting by Rahul B in Bengaluru; Editing by Gopakumar Warrier)

Stocks treated in this article : Domino's Pizza, Inc., Domino's Pizza Group PLC.