UK bakery Greggs posted a 2.6 per cent increase in like-for-like sales in the fourth quarter, supported by strong trading over the Christmas period.The company achieved a 3.1% rise in like-for-like sales during the Christmas and New Year period in the five weeks ended January 4th. This compared to a 2.9% decline in 2012.Growth was driven by core 'food-on-the-go' products including sales of sandwiches, savouries, sweet bakery goods and drinks. The firm also introduced a limited range of Christmas favourites, including Festive Bakes and sweet mince pies.Greggs, however, reported a 0.8% fall in underlying sales over its fiscal year 2013, due to difficult trading conditions earlier in the year. During the year, the group opened 68 new shops and closed 68 shops, with 70% of openings away from high streets. The business finished the year with a net cash balance of £24.6m, up from £19.4m in 2012. "We anticipate that we will report full-year results in line with our previous expectations when we make our preliminary announcement on February 26th," Greggs said. "Whilst we have been encouraged by the improvement in like-for-like sales we face a year of significant change as we continue to implement our plan to reshape the business to compete more effectively in the food-on-the-go market. As we have previously indicated the costs of this are likely to constrain profit growth over the next two years; however we are confident that we are building a platform for sustainable long-term profitable growth."The stock was up 8.25% at 482.25p by 10:22 on Thursday.RD