The black hole in the UK's largest company pension schemes stands at £36 billion, a study showed today.

Volatile markets pushed the deficit as high as £54 billion in January before it plummeted to £29 billion in April and settled at £36 billion in July - which out to be broadly the same as this time last year, the comprehensive study by actuarial consultants Lane Clark & Peacock found.

Company contributions have risen to record levels - £12.5 billion in 2005, up 12 per cent on the previous year, the survey also found.

The highest contributions were paid by HSBC at £1.3 billion and Royal Dutch Shell at £702 million.

Only five companies in the FTSE 100 reported a pension scheme accounting surplus. These were Associated British Foods, Gallaher Group, Johnson Matthey, Old Mutual and Schroders.

This week, department store chain Debenhams, with stores nationwide and thousands of staff, confirmed it is to close its final salary pension scheme to both new and existing members.

The controversial decision followed 18 months of negotiations with the scheme's trustees.

And support services group Rentokil angered unions in December when it became the first FTSE 100 Index to close its final salary schemes to existing members.