LONDON, March 11 (Reuters) - Shell, the world's largest liquefied natural gas trader, has declared force majeure on LNG cargoes it buys from QatarEnergy and sells to its clients worldwide, three sources told Reuters on Wednesday.

Qatar, the world's second-largest exporter of LNG, announced a production halt at its 77 million tons per annum (mtpa) facility last week and declared force majeure on LNG shipments.

Shell declined to comment.

Other Qatari LNG buyers, including TotalEnergies and some Asian companies, have received force majeure notices from Qatar and told customers they would not be selling them Qatari LNG as long as the facilities remain shut, two other sources said.

A source close to TotalEnergies said the French oil and gas major has not declared force majeure, a notice used to describe events outside a company's control, such as a natural disaster, which usually releases it from contractual obligation without penalty.

Both Shell and TotalEnergies have long-term partnerships with QatarEnergy and are partners in the company's massive North Field expansion project which aims to boost capacity by 2027.

Analysts estimate Shell takes 6.8 mtpa of Qatari LNG, while TotalEnergies takes 5.2 mtpa.

Qatari Energy Minister Saad al-Kaabi told the Financial Times last week that it would take "weeks to months" to return to normal deliveries, even if the war ended today. QatarEnergy declared force majeure on LNG shipments on Wednesday.

Sources told Reuters last week that the force majeure notices sent to clients stated that LNG deliveries for March will not be affected, with the impact being felt as of April.