The families are seeking 15 million baht for each victim.
The demand was lodged as the victims' relatives negotiated with the airline, the insurance company and Lao authorities on Monday.
Suchai Jirayunont, 58, a representative of the families of three victims _ Phakkawat Atiratanachai, Kanueng Chartkasamchai and Veekij Busarawuthanu _ urged the insurance firm to pay the maximum compensation of US$500,000 (15 million baht) to each family.
It is unknown whether the insurance company agreed.
An argument reportedly broke out during the negotiations as the Thai relatives were unhappy with the slow progress in the search operation for the two other Thai victims _ Yangyong Apaanan and Nipol Mengsee.
The five Thais were among 44 passengers and five crew on board Lao Airlines Flight QV301 which crashed into the Mekong River near Don Khor islet last Wednesday in Champassak's Pakse district during a landing attempt at Pakse International Airport. Bad weather was blamed for the crash.
Forty-three bodies have been recovered from the Mekong River so far. One more Thai body was identified yesterday, that of Veekij.
Three Thai bodies have now been identified. They are Phakkawat, Kanueng and Veekij.
Their bodies will be returned to Thailand today by a C-130 transport plane.
Deputy Minister of Laos' Public Works and Transport Rattanamanee Khounewong yesterday apologised to the victims' relatives.
Lao Airlines would initially pay $5,000 (150,000 baht) to the relatives of each of the Thai victims and provide air transport to return their bodies to their hometowns in Thailand.
Sommat Phonsena, Lao Minister for Public Works and Transport, said the search team had located the crashed plane's black box. Divers are working to recover the box, he said.
Mr Sommat stressed Laos will not stop the search operation and will continue efforts to recover all the bodies and the aircraft wreckage.
Maj Gen Wallop Raksanoh, chief of the Thai military search team which has been helping Lao authorities with the search, said his team ended their operations yesterday as their Lao counterparts confirmed that they were capable of retrieving the rest of the passengers' bodies and the plane wreckage themselves.
The Thai team will withdraw from Pakse today, he said.
Wilawan Apaanan, 29, a sister of Yangyong, said she was concerned about what would happen to the search operation after the Thai team withdrew. She urged international organisations to help in the search.
Meanwhile, the Lao government held a mourning ceremony for the victims at Champassak provincial office about 2pm yesterday.