Rangers administrators to sue former lawyers
"We have instigated legal proceedings against Collyer Bristow, the former lawyers of the club, and The Rangers FC Group Limited in the High Court in London for substantial damages suffered by Rangers Football Club," joint administrator Paul Clark said in a statement on the club's website.
The financial details of the damages claim were not disclosed but the BBC reported Duff & Phelps were seeking 25 million pounds.
Rangers were forced into administration in February after running up a debt of nine million pounds in unpaid taxes since Scottish businessman Craig Whyte took an 85 percent stake in the club last May.
Founded in 1872, they have been domestic champions 54 times, a world record, including for the last three seasons and won the old European Cup Winners' Cup in 1972.
Duff and Phelps said it remained their intention to announce a preferred bidder for the club this week.
They are considering two bidders after The Blue Knights consortium, led by former Rangers director Paul Murray, withdrew its bid on Monday.