Eurostar Group Ltd., operator of high-speed passenger trains between London, Paris and Brussels, canceled all services for a second day, citing unseasonably cold weather in northern France.

The company can't guarantee that a full service will resume before Christmas, Eurostar Chief Executive Richard Brown said in a BBC interview today. The approximately 28,000 passengers affected by today's suspension can request a refund or reschedule their journey, London-based spokesman Paul Gorman said.

All services were suspended yesterday after four Eurostar trains broke down in the Channel Tunnel the previous night. A special service bringing passengers back from Paris broke down in the southeast English county of Kent. Brown said in an interview with Sky News that the temperature change on entering the tunnel created condensation that caused the electrical systems in the locomotives to fail.

"Eurostar does not want to cause its passengers any further disruption and will be conducting a program of 'test trains' to better understand the problems that have been occurring," spokeswoman Lesley Retallack said in an e-mailed statement yesterday.

'Rigorous Review'

Eurostar will be seeking talks with Groupe Eurotunnel SA, the Channel tunnel's operator, to mount a "thorough and rigorous review" of the breakdowns, Brown told the BBC.

"We are all interested in conducting an investigation into the five Eurostars breaking down as we would into any safety event in the Channel tunnel," John Keefe, a U.K.-based spokesman for Eurotunnel, said today in a phone interview.

Temperatures in northern France fell to as low as -8 Celsius (17 Fahrenheit) on Dec. 18, "significantly lower than usual," Eurostar's Gorman said.

"The more humid, warmer environment in the 30-mile (48- kilometer) tunnel affects the electrical systems" in the train engines, Gorman said. In the 15-year history of Eurostar, such incidents "have not occurred on this scale before," he said.

In northern France today, temperatures were forecast to hover at about 0 Celsius with snow possible, according to the French meteorological office.

Normal Shuttle Service

Passenger and car shuttle services between Folkestone and Calais were running normally this morning, with a "residue" of freight problems, Eurotunnel's Keefe said. Services ran on a reduced basis yesterday.

Eurotunnel's locomotives and shuttles are maintained so that rapid temperature changes don't affect them, the tunnel operator said.

Freight services to France were suspended yesterday after French authorities closed motorways to trucks due to weather conditions, said Keefe. "Several thousand" trucks were backed up on the M20 motorway in Kent as a result, he said.

Trucks coming from Dover were stuck at Calais port because France's A16 motorway was closed to them, Gerard Baron, a spokesman for Port de Calais, said yesterday. About 8 inches (20 centimeters) of snow fell in the region on Friday night, he said.

Flights from Roissy Charles de Gaulle, Paris' main airport, were still experiencing one-hour delays on average after 1.2 inches of snow disrupted takeoffs and landings, said Eric Heraud, a spokesman for the French civil aviation administration.

About 40 percent of flights from Charles de Gaulle were canceled this morning and 20 percent were canceled this afternoon to absorb the delays, Heraud said. The authority expects traffic to return to normal at 6 p.m. Paris time, as snow stopped falling at around 2:30 p.m., he said in a telephone phone interview. There were no flight delays or cancellations at Orly, Paris' second largest airport, this afternoon, he said.