The army seized power in November just days after the country's presidential elections, overthrowing president Umaro Sissoco Embalo and suspending the electoral process.

The junta said it was taking control for one year and appointed N'Tam -- a close Embalo associate -- as transitional president.

It has set December 6 as the date for new presidential and legislative elections meant to return power to civilians.

N'Tam had previously held the rank of brigadier general. Under Thursday's decree, he has been "elevated to the rank of major general", now carrying four stars instead of two.

The junta claimed it seized power in November to prevent bloodshed between supporters of rival candidates in the elections.

Both president Embalo and opposition candidate Fernando Dias had declared victory even as the country still awaited official results.

Before November, the coastal west African country had already undergone four military takeovers and a host of attempted insurrections since gaining independence from Portugal in 1974.

Crippling poverty, chaotic administration and political chaos have also made Guinea-Bissau a fertile ground for corruption and drug smuggling.