FREETOWN, July 1 (Reuters) - Travellers cheques denominated in West African Units of Account (WAUA) officially went on sale on Thursday in the Economic Community of West African States (ECOWAS), the West African Monetary Agency (WAMA) said.

ECOWAS covers 16 countries -- Benin, Burkina Faso, Cape Verde, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone and Togo.

The WAUA will follow the value of the Special Drawing Right and the cheques will be in denominations from five to 100 WAUA.

George Osaka, WAMA director of research and operations, told Reuters that WAMA's Freetown headquarters would set an exchange rate against the various West African currencies once every two weeks. The cheques would then be exchangeable around the region at that rate for two weeks.

Banks will be allowed to make a spread of a maximum of one percent around the rate when buying or selling the cheques but will not be allowed to charge commission, according to central bank officials in the region.

There has been wide publicity for the cheques in Freetown this week and campaigns have been launched in certain other ECOWAS countries.

The cheques were not available in banks in Abidjan, and publicity campaigns in Ivory Coast and the other seven CFA franc countries had been delayed for technical reasons, an official at their common central bank, the Dakar-based BCEAO, said.

ECOWAS officials see the travellers cheque as a step towards monetary union and are hoping that they will stimulate regional trade.