Volcanic ash from Eyjafjallajokull caused a dip in sales at The Restaurant Group (TRG).
TRG, which counts Frankie and Benny's, Chiquito and the Brunning & Price pub estate among its brands, recorded like-for-like sales up 0.5% on last year for the 8 weeks to 2 May.
However, it estimated like-for-likes would have been 1.5% ahead if the ash had not led to a major drop in trade at its 50-strong Concessions division, which mainly operate at airports.
"Our Concessions division was in good growth until the ash cloud halted air travel and we saw five days of sales decline in excess of 90% in our airport business," said chairman Alan Jackson.
"Trade in our Concessions business is now returning towards normal (although suspension of some flights due to the new ash clouds over Scotland and Ireland has had a small impact over the past two days) and our Leisure division is also trading well.
"We estimate that, to date, the disruption has resulted in a £0.5m impact on our Concessions division's profit and loss account, comprising £0.3m of cash costs and foregone profit opportunities of £0.2m."
Total sales for the period were up 6% on 2009. TRG has opened seven new sites in 2010 and plans to open a further 15-25 during the year.