UK companies should consider splitting their occupational pension schemes to avoid potentially crippling payments if Scotland becomes independent, a leading actuarial consultant has warned.

Donald Campbell, of pension consultants Xafinity, said firms should prepare to run separate Scottish and UK schemes for staff.

The call follows a report from the Institute of Chartered Accountants of Scotland (ICAS) which highlighted an EU directive prohibiting firms from operating underfunded "cross-border" pension schemes.

ICAS warned companies would have to find billions of pounds to plug black holes in their pension funds immediately if Scotland split from the UK.

The professional body urged the Scottish and UK Governments to address the issue ahead of next year's independence referendum.

Mr Campbell said firms were most likely to split UK-wide defined benefit schemes, though the move would add to the cost of providing pensions. "Prior to the directive coming into force it was quite common for UK and Ireland employers to have cross-border schemes," he said.

"But Ireland and the UK were given a few years' grace to implement the directive where there were cross-border issues."

Most pension schemes do not have the funds to cover payments to present and future members.

Many are operating 10 or 15-year recovery plans to bring their assets more closely into line with their liabilities, a move allowed within a single EU country. However, the directive would force firms to plug the gaps immediately unless a deal with Brussels could be struck.

The Scottish Government dismissed ICAS's concerns, saying cross-border pension arrangements were "commonplace" and citing the measures introduced to deal with UK and Ireland schemes when the EU rules were introduced.

SNP ministers are expected to publish a report on pensions before the Government issues its full blueprint for independence in November.