* Lisbon airport at maximum capacity
* Britons lead tourist rankings to Portugal
* Pestana group posts record year in 2018 with new hotels
LISBON, Jan 14 (Reuters) - Portugal's long-running tourism boom is set to move decisively into reverse in 2019 due to capacity constraints at Lisbon airport and a drop in British visitors because of a Brexit-hit pound, Portugal's biggest hotel group told Reuters.
Jose Theotonio, chief executive of the Pestana Group which operates 94 hotels, said he had already noticed a dip in British guests as they turn to markets like Turkey, Egypt and Tunisia where local currencies have depreciated more than sterling.
"I hope, at some stage, there will be good judgment and a deal is reached to avoid a 'hard Brexit'," Theotonio said in an interview. "But Portuguese hotels are going to have to adjust prices to keep the English market."
He predicted lower revenues from British tourists this year in key resort destinations like the Algarve and Madeira as competition from eastern Mediterranean markets hots up.
Britons are the leading tourist visitors to Portuguese hotels, representing about 15 percent of the total 13 million.