(Adds details from Homs)
* Group records rise in death toll since talks began
* Assault part of battle to control central Syria, borders
* Opposition in Geneva proposes U.N.-monitored ceasefire
* Government rejects transition talks as negotiations falter
* Russia, Western powers at odds over U.N. aid resolution
By Erika Solomon
BEIRUT, Feb 12 (Reuters) - More Syrians have been killed in the three weeks since peace talks began than at any other time in the civil war, activists said on Wednesday, as troops pounded rebel towns on the Lebanese border and negotiations faltered in Geneva.
More than 230 people have been killed every day in Syria since Jan. 22, when international mediators brought President Bashar al-Assad's government and its opponents together, the British-based Syrian Observatory for Human Rights said. That is more than in any other three weeks since the war began in 2011.
It is unclear how far the bloodshed is a consequence of the talks, as both sides seek to improve their bargaining positions by gaining territory. On Wednesday, Assad's army and fighters from Lebanese ally Hezbollah pounded the strategic border town of Yabroud where rebels prepared to resist a ground offensive.
The United Nations says more than 130,000 Syrians have been killed in nearly three years of fighting. Totalling at least 4,959, the three-week death toll compiled by the Observatory included 515 women and children. The group estimated about a third of all the dead were civilians.
"This is the highest average we have had," said Rami Abdelrahman of the Observatory as the group urged a suspension of negotiations at Geneva if there was no immediate ceasefire.
There was little sign of an early breakthrough on the third day of a second round of talks in the Swiss city.
The opposition, which has little sway over rebels fighting on the ground, called for a transitional governing body to oversee a U.N.-monitored ceasefire and expel foreign fighters in a paper that avoided any mention of Assad - whose departure the government delegation has refused to discuss.
The confidential paper, seen by Reuters, did not draw an immediate official response from the government, although the foreign minister said driving out foreign fighters could be worth discussing in time - rare common ground.
Foreign, anti-Western Islamists are a major force among the otherwise Western- and Arab-backed rebels. The opposition wants rid of Hezbollah and Iranian auxiliaries fighting for Assad.
Wednesday was the last day of a three-day extension of a humanitarian ceasefire allowing the delivery of aid and evacuation of civilians from the city of Homs although it could be extended again, the city's governor Talal al-Barazi said.
Syrian army soldiers used mobile phones to try to take pictures of the evacuees, convinced they were among the rebels fighting there, in scenes illustrating the fear and suspicion unleashed by the conflict that has torn the country apart.
Another plainclothes member of the security forces was overheard saying his role was to greet each of the evacuees to see if their accents betrayed foreign nationality.
The fighting around Yabroud is part of a broader "Battle for Qalamoun", the mountainous border area near Damascus that offers control over routes to Lebanon and between the capital and the coastal stronghold of Assad's minority Alawite sect.
Government forces seem to have had the better of recent fighting, but outright victory seems out of reach. As U.S. intelligence chief James Clapper put it on Tuesday, a "prolonged stalemate" seems likely, extending what he described as "an apocalyptic disaster" in Syria.
A spokesman for the rebel unit Liwa al-Ghuraba at Yabroud, said Hezbollah fighters and Assad forces were trying to position themselves on nearby hilltops to attack the town.
"They are gathering their forces with the hope of taking the border road," said spokesman Abu Anas. "Right now no one is moving in Yabroud. The rebels are blocking the offensive.
"The hospital is filling up with wounded."
Assad's forces had, he said, sent envoys in the days leading up to the attack to try to convince leading citizens in nearby towns to accept a truce. Some villages accepted, but most towns, like Yabroud, refused, Abu Anas said.
"The battle for Qalamoun was supposed to just be a propaganda campaign," he said.
"But the regime got itself in a mess: the army sent people to convince us there could be a peaceful solution if we raised the government flag and took photos. Instead, we refused."
Concern about talks running into the sand prompted the mediator in Geneva, Lakhdar Brahimi, to bring forward by a day to Thursday a meeting with Russian and U.S. officials in an effort to get Washington, which backs the rebels, and Assad's ally Russia, to press their proteges.
Continued strains between Russia and other world powers that have so far blocked U.N. action against the Syrian government showed little sign of easing. Russia said it would veto a U.N. resolution on aid, saying its wording seemed meant to open the way for foreign military action.
And a foreign ministry spokesman in Moscow said Barack Obama had "intentionally distorted" the Russian position in remarks the U.S. president had made on Syrian aid on Tuesday.
The struggle on the Syrian border risks fuelling sectarian tensions in Lebanon, where Sunni-Shi'ite divisions deepened by the conflict in Syria have already triggered instability.
The violence in Syria has set off a wave of tit-for-tat car bombings in Lebanon, as well as street clashes. On Wednesday, the Lebanese army arrested an al Qaeda militant whom security sources called a "mastermind of car bombs".
In Geneva, opposition and diplomatic sources said the transition proposal from the opposition avoided reference to Assad, in line with a text agreed by world powers in June 2012 which calls for a body with full executive authority but leaves the president's fate open - something Russia has insisted on.
Asked why the document did not go into the fate of Assad, the opposition's chief negotiator, Hadi al-Bahra, told Reuters:
"We can no longer talk about one person as the sole embodiment of Syria. We deliberately presented a legal paper."
The memorandum was presented to mediator Lakhdar Brahimi and the government delegation. The transitional authority will be "the only legitimate body that represents the sovereignty and independence of the Syrian state and is the only one that represents the Syrian state internationally", the paper said.
The Syrian government delegation said that negotiations must focus first on combating terrorism - its term for all anti-Assad fighters - and called parallel talks on the opposition's priority of a transitional government a "fruitless" idea.
The opposition document says the transitional body would "prepare and oversee a total ceasefire by taking immediate measures to stop military violence, protect civilians and stabilise the country in the presence of U.N. observers." (Additional reporting by Steve Gutterman in Moscow, Mariam Karouny and Laila Bassam in Beirut and Stephanie Nebehay, Khaled Yacoub Oweis and Oliver Holmes in Geneva; Writing by Erika Solomon and Alastair Macdonald; editing by Anna Willard and Alistair Lyon)