The partial deal will be regarded as a victory for the regime, since if only combatants remain it will be able to pursue attacks on the city, including aerial attacks, without being accused of targeting the innocent.
However, some progress was keenly sought by the opposition, which wanted to prove to its sceptical support base that the talks would be useful and were not just an excuse by its Western backers to abandon it and leave President Bashar al-Assad in place.
Homs was among the first centres of armed resistance to the Assad regime, and rebels in the old city have held out against regime attack for two years, even after other enclaves such as Baba Amr fell to heavy regime bombardment.
"There are about 800 families, or 5000 people, under siege here," a woman who gave her name as Mirna, said by Skype from inside. "Eight people have died from hunger, including four children. The city has been under total siege for 595 days. Food and medical supplies have run out, and we are under continuous bombardment. Minor injuries lead to death because of the lack of medical equipment."
The second full day of face-to-face peace talks in Geneva focused on humanitarian issues including an exchange of prisoners.
The Homs proposal had been described as a "low-hanging fruit" by opposition spokesmen yesterday, but even it proved difficult to agree.