(Reuters) - British pubs group JD Wetherspoon (>> J D Wetherspoon plc) reported strong comparable sales in the Christmas period and said year-to-date underlying pretax profit was slightly ahead of its expectations.

The owner and operator of more than 900 pubs in Britain and Ireland said like-for-like sales for the 12 weeks to Jan. 21 rose 6 percent.

The company, however, warned that a similar performance would be "difficult to achieve" in the second half of its financial year ending July.

"We face significant costs in the second half in areas which include labour, business rates and the sugar tax. There will also be some uncertainty as to the effects on our business of the FIFA World Cup," Chairman Tim Martin said in the statement.

Wetherspoon, like other operators in the sector, has been battling rising costs due to the government's National Living Wage initiative, higher property prices and unfavourable currency exchange rate.

JD Wetherspoon's performance contrasts to that of Marston's (>> Marston's PLC), which on Tuesday said business in the Christmas period was marred by snowy and icy weather.

Wetherspoon, which opened three new pubs since the start of the financial year and sold 10, said it intended to open 10 pubs in the current financial year.

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

Stocks treated in this article : Marston's PLC, J D Wetherspoon plc