An Amadan,
As far as I know, if you leave a commercial semistate db scheme (funded) early you have a number of options:
If you leave after two years you can defer your benefits;
this means that when you reach retirement age you can draw down a pension which is a proportion of the salary you were earning when you left based on the number of years you served. To the best of my knowledge this "leaving salary" is not indexed for general inflation or wage inflation. If inflation took off you could face a significant loss. Also as mentioned in another thread if the semistate is not around in 20 years (Irish Fertilisers etc) and the fund cannot fully meet its liabilities you may not get as much as you expected.
Another option is, if you are leaving to take up an other semi state (local authority, civil service health board) which offers a similar scheme. Some of these bodies operate a "knock for knock scheme " which means they might accept transferees together with their years service. If you are accepted you can transfer your service to the new scheme.
A third option is to get a transfer bond and transport the value of you pension into a third party pension fund. (Others who contribute to this discussion group are far more qualified to comment on this option). If your retirement date was a long way away and you took the view that the markets were going to perform well this might be the best option.
I hope this is of use to you. I am far from a pensions expert and would advice you to talk to the trustees of your prospective pension fund and also get your hands on the scheme booklet which outlines the benefits. Some of the best people to talk to in this regard are employees two to three years short of retirement or the pensions administrators in the company. I would also talk to an independent pensions advisor who would provide a better view of the "bigger picture".
Some of these schemes have "hidden" benefits in the form of "Spouses and Childrens" benefits and "Death in Service" benefits. It would be worth your while to find out about these as well.
Good luck in the new job,
ajapale