Tamil Nadu Chief Minister J. Jayalalitha Thursday sought Prime Minister Manmohan Singh's intervention to end a four-day strike by liquefied petroleum gas (LPG) tanker operators in the state.

The strike by tanker operators who carry LPG used for cooking in India arose from a contractual disagreement between the supplier companies and the operators who are demanding changes in LPG transportation tenders till 2007.

"There is nothing that can be done at the state level on the issue," Jayalalitha told the prime minister in a letter.

"The union petroleum minister is in charge of the matter and will need to evolve a quick solution," she wrote.

About 2,000 LPG tankers have stayed off the roads in south India as the strike by the bulk transporters entered the fourth day, industry sources said.

There are over five million domestic LPG connections in Tamil Nadu.

The Salem-based Southern LPG Transport Association, which operates about 65-70 LPG tanker lorries, and Nammakal-based Southern Region LPG Transporters Association that operates about 150 tankers have not joined the strike.

Jayalalitha, however, pointed out that 13 of the 16 bottling plants in Tamil Nadu had shut down from Thursday and this could cause a shutdown in supply to domestic consumers in most areas of the state.

She said bottling of LPG cylinders in Tamil Nadu is done on a daily basis on the "just-in-time" inventory principle and supplies are made on a daily basis to householders.