* Third Geneva round agreed but no date set
* Britain, France blame Assad for impasse
* ICRC says Syria still denying access to most areas
By Oliver Holmes and Tom Miles
GENEVA, Feb 15 (Reuters) - International mediator Lakhdar Brahimi apologised to the Syrian people for the lack of progress at peace talks in Geneva after their second round ended on Saturday with little more than an agreement to meet again.
As it became clear that the talks had not even broached the subject of a change of leadership in Syria, both France and Britain, who back the opposition, blamed President Bashar al-Assad for the impasse.
Underlining the gaping rift that remains between the sides, anti-government negotiators and a diplomat said Syria's government had added opposition delegates to a "terrorist list" and had seized their assets.
"I am very, very sorry and I apologise to the Syrian people ... their hopes ... were very, very high here, that something will happen here," Brahimi told journalists.
An early agreement to evacuate people from the besieged city of Homs had raised false expectations the talks would make greater progress, said Brahimi.
Saturday's last session of the second round of the talks was "as laborious as all the meetings we have had, but we agreed on an agenda for the next round when it does take place", Brahimi added.
The head of the International Committee of the Red Cross (ICRC) also stressed how meagre the results had been, saying the Homs evacuation had not heralded any wider improvement in humanitarian access to civil war zones where the United Nations says up to 3 million people are beyond its reach.
The three-year-old Syrian revolt against President Assad began as peaceful street protests but transformed into an armed insurgency after a fierce security force crackdown.
Fighting has killed more than 140,000 people - more than 7,000 of them children - according to the Syrian Observatory for Human Rights, and is destabilising the country's neighbours.
The pro-opposition Observatory, a British-based monitoring group, said around 6,000 Syrians have been killed since the latest talks started last month, the fastest death rate recorded since the country slid into conflict in 2011.
Brahimi said the points to be discussed at the next Geneva round included violence and terrorism, a transitional governing body, national institutions and national reconciliation.
However, he added, the Syrian government first wanted to deal with the issue of combating "terrorism" - the word it uses to describe armed opposition to Assad's rule - and had refused to deal with any other points until that was resolved.
The Algerian-born diplomat said both sides would need to reflect on their responsibilities before round three, and that the government in particular had to accept that the main objective of talks was transition.
Syrian government delegate Bashar al-Jaafari, said the opposition wanted the issue of "terrorism" to stay open-ended. "Whoever refuses to fight terrorism is part of terrorism," he told reporters after the final session.
Opposition National Coalition spokesman Louay Safi said there was "nothing positive" to take from round two, which lasted a week. The final session lasted around half an hour.
Both the UK and France, who back the opposition, said the government was to blame for the lack of progress.
British Foreign Secretary William Hague said Brahimi "made clear that the regime refused to discuss the issue of a Transitional Governing Body, an issue that is at the heart of the negotiation and an essential means of ending the conflict."
French Foreign Affairs Minister Laurent Fabius condemned the attitude of the Syrian government and said the opposition Coalition "adopted a constructive position throughout the negotiations."
In Geneva, one diplomat said the opposition negotiators had discovered a few days ago that most of the team was on a "terrorism list" of 1,500 activists and rebels opposed to President Assad.
FEARS OF GROUND ASSAULT
Thousands of people fled a rebel-held western Syrian town, Yabroud, on Friday after it was bombed and shelled in an operation that has stirred fears of a major assault by ground troops, the United Nations said.
Al-Manar television, run by Lebanon's Hezbollah, said the Syrian army had advanced in the Yabroud area, seizing control of the town's main road and a nearby border crossing that it said was used for smuggling.
ICRC President Peter Maurer said there were many other besieged areas besides Homs, with more than a million people living in very difficult conditions.
"Negotiations with the Syrian authorities and opposition groups have not resulted in meaningful access or a firm commitment to respect the basic principles of international humanitarian law," he said. "This pattern has again played out in Homs over the last week."
The rebels come mainly from Syria's majority Sunni Muslims and have been joined by radical Sunni groups such as al Qaeda and other foreign militants.
Shi'ite Muslim Iran and the powerful Lebanese Shi'ite movement Hezbollah have thrown their weight behind Assad, who is from Syria's minority Alawite sect, an offshoot of Shi'ite Islam, and whose family has dominated Syria for 44 years. (Additional reporting by Erika Solomon in Beirut, Steve Holland in California and John Irish in Paris; Writing by Tom Heneghan; Editing by Andrew Heavens)