Talks between Somalia's interim government and Islamists who control the capital are expected to resume in Sudan this week.
Officials in Mogadishu say the Islamists will be represented by Sheikh Sharif Sheikh Ahmed, a senior leader of the Council of Islamic Courts.
Officials in the government base of Baidoa say the government will be represented by parliament speaker Sharif Hassan.
The two sides have not met since late June, shortly after militias loyal to the Islamic courts seized control of the capital from secular warlords.
At the last talks, the sides reached a non-aggression and mutual-recognition pact. But further talks have been delayed and tension has been growing over the Islamists' expansion across southern Somalia.
The government accuses the Islamists of breaking the June agreement, while the Islamists oppose the presence of Ethiopian troops protecting the government.
Ethiopia officially denies sending troops into Somalia, but numerous eyewitnesses have reported their presence in Baidoa and other areas.
The fragile government is also seeking foreign peacekeepers for Somalia, which has not had an effective central authority in 15 years.
Some information for this report was provided by AFP and Reuters.