Tesco is on track to become the biggest convenience store chain following a £200 million sales increase this year, a report said.

The retail giant could steal Spar's crown as the most successful neighbourhood shop chain during 2006, according to Verdict Research analysts.

Tesco's share of the sector grew more than any of its competitors this year. Its sales, from outlets including Tesco Express and Tesco Metro, rose by £200 million to £2.4 billion in 2005, Verdict said.

The supermarket giant now has the joint second largest slice of the convenience store market, along with Irish operator Musgrave, which owns Londis and Budgens.

Verdict Research retail analyst Nick Gladding said: "Spar is predominantly a franchise operation, with limited control over individual stores, making it harder to deliver sales growth initiatives."