Clients of Lehman Brothers in Europe may have to wait longer to get their assets back after a judge blocked a process to speed up the unwinding of the bankruptcy, accountants warned on Friday.

PricewaterhouseCoopers (PwC), administrators to Lehman Brothers International (Europe), had asked the High Court to approve a plan to accelerate the return of client's assets, tied up in the bank since its collapse last year.

But the UK High Court said it had no jurisdiction to sanction the so-called scheme of arrangement, according to PwC, which had sought to return $9 billion of client assets from the first quarter of 2010.

"This judgment is disappointing as it could create further delay for many clients," PwC said in a statement.

Lehman's demise in September brought the global financial system to the brink of collapse, and accountants expect to have to work for years to sort out billions of dollars worth of assets left locked in its accounts.