The average UK pension fund booked a negative annual return for the first time since 2008 last year, nudged into the red by a marked rise in stock market volatility caused by the euro zone crisis, an early survey of the industry showed on Thursday.

Returns were minus 0.9 percent for the year, BNY Mellon estimated, due to a negative return of 4.8 percent during the third quarter. All other quarters of the year saw slightly positive returns.

2011 was a very volatile year for assets of pension funds, Alan Wilcock, performance and risk analytics manager at BNY Mellon Asset Servicing, said in a statement.

This volatility is reflected starkly in emerging market and Europe ex-UK equities, which posted annual returns of minus 17.8 percent and minus 15.2 percent respectively.

Allocations to UK equities reached an all-time low in 2011 of 19 percent, compared with 47.1 percent 10 years ago, BNY Mellon said.

Despite recording an estimated average return of 8.4 percent a year since the financial crisis first erupted in 2008, Wilcock is cautious about the outlook.

Although returns were only slightly negative for the year as a whole, higher inflation and lower long-term interest rates will have added to pension scheme liabilities, he said.

Reflecting the heightened concern over the future path of inflation, UK pension funds almost tripled holdings of index-linked Gilts to 15 percent from 5.7 percent over a 10 year period.

Safe-haven plays also saw fixed-income allocations rise to 29.5 percent from 18.5 percent, most significantly within non-Gilts, the survey shows.

BNY Mellon will publish the full report at the end of March.

(Reporting by Anjuli Davies; Editing by Sinead Cruise and David Holmes)