(Adds detail, PwC comment)
LONDON, May 23 (Reuters) - PwC, administrator for collapsed British broker Beaufort Securities, said on Wednesday it had revised its estimate for the administration costs to 55 million pounds ($73 million) over two years from 100 million pounds over four years.
Beaufort was declared insolvent in March after the U.S. Department of Justice named it as one of 10 defendants charged over its alleged role in a more than $50 million stock fraud and a laundering scheme involving a work by Pablo Picasso.
The change comes after PwC held a meeting with a creditors' committee for the broker, which had 16,000 clients including several junior mining firms.
"It's a complex, evolving situation," PwC joint administrator Russell Downs told Reuters by phone.
"We feel it's the right time to publish a refined cost estimate."
PwC has frozen around 500 million pounds in client assets, and is aiming to return the funds to clients in September, though Downs said this was "an ambitious timeline."
Creditors of Beaufort, including several mining firms, had said they could not see any justification for PwC's earlier cost estimate.
($1 = 0.7492 pounds) (Reporting by Carolyn Cohn and Barbara Lewis; Editing by Mark Potter)