Some pension specialists see little hope in tinkering with the system.

Because defined-benefit plans have been subject to increasing regulations, they are becoming less attractive for businesses to offer, pension specialists said.

That lack of disclosure has some regulators and pension specialists worried.

Other pension specialists expressed similar worries about more problems emerging within Putnam.

Some pension specialists think eliminating the accounting incentive could reduce the risk.

And it is likely to fuel further controversy among pension specialists about whether stocks are an appropriate investment.

Of those, many are thought to have frozen the benefits, pension specialists say, so that additional years of service no longer build a bigger pension.

Detailed information about individual plans is not disclosed by companies, but pension specialists say that about two-thirds of their assets are typically invested in stocks.

The question preoccupying American pension specialists is what lessons they should draw from the Chilean experience.

This erosion is known among pension specialists as "wearaway."