You have three clear-cut choices for the sharing of pension funds:

The Offsetting option

With this option, pension benefits are ‘traded off’ against any other wholly owned assets the couple may have – the matrimonial home, the value of a business, or any other types of investments. In return for giving up the benefits of the other assets, the party with the pension rights gets to keep those rights in totality.
Pros: a fairly straightforward arrangement which enables the couple to make a clean break.
Cons: the pension may be worth more (or less) at any given point than all the other assets combined, making it more difficult to reach a mutually agreeable figure. Also, and importantly, the partner without the pension funds will often end up with no provision whatsoever. This creates significant issues at retirement and often limited time before retirement for the individual to improve their position.

The Earmarking option

A court can rule (through an Attachment Order) that when the divorced party with the pension rights starts drawing pension benefits, a pre-agreed percentage of the benefit must be paid to the ex-spouse. Although the actual amount payable is decided at the time of the divorce, either party can apply to the court at any time to have the amount varied.
Pros: the pension member stays in control of the pension fund.
Cons: Earmarking is not a ‘clean break’ arrangement; the ex-spouse has no control over the pension fund and receives no income until the spouse with the pension rights decides to draw benefits. Furthermore, Attachment Orders no longer apply if the scheme member dies before reaching pensionable age, or if the beneficiary of the Attachment Order remarries.

The Pension Sharing option

On divorce (but not after) a couple can divide the assets in the pension scheme so that the couple have separate independent pensions, either with the same or a different provider.
Pros: a clean break arrangement where the ex-spouse has control over how their share of the fund is invested, does not have to wait until his or her ex-partner retires to take benefits, is free to remarry without forfeiting any pensionable rights and is not penalised financially if his or her ex-partner dies before reaching pensionable age.
Cons: the pension holder may wish to avoid this as they have the most to lose.