The coming year could put a serious strain on the pension schemes of some of the UK�s biggest companies which are still heavily invested in equities and property, says a new analysis.

The coming year could put a serious strain on the pension schemes of some of the UK's biggest companies which are still heavily invested in equities and property, says a new analysis.

Members of the FTSE-100 could "lose" up to £80bn through their funds' exposure to the long-term assets in their final salary schemes, according to consulting firm Deloitte.

The figure is an estimate of the maximum loss which pension funds at Footsie firms could face in the event of adverse market movements.

Many big schemes are still heavily invested in the riskier asset classes, and volatility combined with annual accounting rules, could force firms to pump in cash to plug gaps if their values slump, Deloitte said.

Between June 2007 and June 2008, UK commercial property values fell by nearly 20%, while the FTSE All-Share index fell by more than 11%.

The aggregate funding of UK pension schemes has slid from a surplus of £15bn at the start of the year to a deficit of £23bn now, in part as a result of sliding equity markets, Deloitte said.

Footsie firms on average are risking about 8% of their market value through their pension schemes, it claimed - though some have more than 100% of market value at risk.

Industrial firms were at the highest risk of a plunge in their schemes' funding, with around 16% of their market value in jeopardy, Deloitte said.

Oil and gas companies have a total of £16bn at risk but their strong market value meant that translated into only 6% of their value.

Firms and pension trustees should de-risk through using bonds or derivatives to match their expected benefit payments or by offloading all or some of their liabilities to a specialist buy-out insurer, Deloitte said.

This week Scottish advisory firms warned of a fresh wave of pension scheme closures in response to the economic and market environment.