Prudential said yesterday that its typical 25-year savings endowment would this year pay out almost £49,500 on maturity compared with under £43,500 at Norwich Union and barely £38,000 at Standard Life.

The Pru, under pressure in its key annuities area of business in the UK, went on the offensive over the performance of its with-profits fund, and also boasted that only 15% of its mortgage endowments (and 10% at Scottish Amicable) were in the "red" zone, well below the proportions at its rivals.

The insurer said its £85bn with-profits fund was invested over 70% in equities and property, below the 76% of 2005 but ahead of the previous three years (and way ahead of the current allocations at NU and Standard Life.) The fund returned 12.4% last year, enabling most policy values to rise by at least 10%, which is not, however, out of line with competitors.

The Pru also followed its rivals in refusing to increase yearly bonus rates. Amid a welter of detail on every aspect of its pay-outs, it stated: "Annual bonus rates are being maintained on all policies."

Gary Shaughnessy, managing director of life and pensions, said: "Our investment performance over five and 10 years has continually outperformed a number of market indices and the vast majority of other with-profits funds. This demonstrates clearly that with-profits, by being invested in an actively managed, well-run and financially strong fund, can produce good returns for the cautious investor."

The insurer rubbed in the salt by citing plaudits from Ned Cazalet of Cazalet Consulting, who has said the Pru "has got some big market calls right, and its tactical asset allocation decisions have paid-off, big time" and from James Smith, of Investment Week, who approved its "correct calls on the dot.com bubble and subsequent market recovery".

Prudential said 20-year individual pension pay-outs were up to £40,481 higher than those at its chief rivals, and the 10-year surrender value of a with-profits bond was up to £1259 higher.

Shaughnessy went on: "Our customers have done exceptionally well, not only when compared to investing in with-profits with other companies, but against alternative multi-asset investments, and crucially, at a lower level of risk than direct investing."

The insurer said all of its own endowment policies maturing in 2007 - and around 96% of plans branded Scottish Amicable - will meet repayment targets. Prudential said it expected 11,051 of its endowments to mature in 2007, with an average surplus of £4400.

Of the 790 Scottish Amicable polices expected to miss their target amount this year, the average shortfall was likely to be around £390, it added.

Prudential has about 4.4 million customers investing in its with-profit vehicles. In all, a total of £2.5bn was added to policy values during 2006 as a result of strong performance, the insurer said.

On its asset allocation it said: "We believe broadly that equities offer good value, with a number of markets in Asia and Europe looking especially attractive. UK commercial property generally looks expensive though we have found opportunities in overseas markets in the US, Europe and Asia. The exposure to alternative assets such as hedge funds and infrastructure is expected to increase slowly over time as opportunities arise."

l The Association of British Insurers has reported 29.7% sales growth in UK life and pensions in 2006, the highest rate of growth since the 1990s. Sales reached £15.4bn, boosted by the government's A-Day pension reforms.