Guineans have been attending commemoration services for victims of recent violence, the day before people resume work after a national strike.
The deal emerged after days of intense negotiation
More than 110 people were killed, the majority shot dead by the security forces, during the seven-week dispute.
Businesses, schools and government offices in Guinea remain closed
Trade unions wanted an independent prime minister to carry out reforms, and President Lansana Conte agreed to end the political crisis on Sunday.
The new prime minister is to be chosen from a list compiled by unions and the opposition.
The deal was struck after lengthy talks involving the unions, the president and West African mediators.
A union negotiator, Ibrahima Fofana, told AP news agency that although the strike ended at midnight on Sunday, Monday was a day of prayer devoted to all those who died in the strike-related violence.
According to a statement read out by regional negotiator Mohamed Ibn Chambas, the unions "have decided to suspend the strike call across the whole national territory and they urge workers to go back to work on Tuesday, 27 February."
Guinea's parliament voted on Friday to reject the president's request for an extension of martial law.
Martial law was declared shortly after Mr Conte appointed a close aide of his, Eugene Camara, as prime minister on 9 February.
This proved so unpopular, unrest deteriorated.
"Eugene Camara is no longer the prime minister," Mr Fofana said after the talks.
But the unions stressed the strike could still resume.
"We have to be careful and let him know the pressure is constant," opposition spokesman Mamadou Ba told AFP news agency.
"He's not in the habit of letting his prime ministers do their job."