Strong sales growth at Costa coffee shops helped hotel and restaurant group Whitbread to offset subdued activity in its restaurant division to grow total sales by 9.2% in first quarter.The share price rose by 72p (+4.9%) to 1,557p at 09:00 on Tuesday morning. The group said that the trading momentum during the 13 weeks to 2 June was consistent with the outlook at its full-year results, with like-for-like (LFL) sales up 1.7%, "although our business was adversely affected by the extended Easter and Royal Wedding holiday," said chief executive Andy Harrison.Total sales at Costa jumped by 22.5% with LFL sales in UK equity stores growing by 4%. The chain opened 73 new stores in the period, and plans to add another 300 worldwide in 2011/12. "We will also rebrand 500 units to Costa Express and add a further 200 new units taking the total Costa Express/Coffee Nation estate to around 1,100 units," the group said.Sales at Premier Inn were also strong, growing by 8.1% (LFL: +3%), with revenue per available room (revpar) up by 2.4%."Premier Inn revpar is continuing to benefit from a stronger London market, whereas in the provinces our Restaurants are being impacted in a more difficult casual dining market," Harrison said.Total sales from Whitbread's restaurants - which include the Beefeater Grill and Brewers Fayre chains - edged just 0.2% higher, while LFL sales fell by 1.4%."We are confident that investing in our strong brand propositions of Premier Inn and Costa and introducing further value offers in Restaurants will enable us to win market share and deliver good returns for our shareholders."---BC