* Insurance claims processor under investigation
* Shares resume trade after 43-day suspension
* Britain's SFO looking at accounting practices (Adds company comments, closing share price)
By Noor Zainab Hussain and Vikram Subhedar
LONDON, Aug 6 (Reuters) - Shares of Quindell Plc,the insurance claims processor under investigation by Britain'santi-fraud watchdog, slumped 28 percent on Thursday, their firstday of trading after a 43-day halt.
About 157 million pounds ($244 million) was wiped offQuindell's market value in the latest blow to a company that,less than 18 months ago, was knocking on the door of Britain'sblue chip FTSE 100 index.
Quindell had a market capitalisation of about 2.5 billionpounds in April 2014, before a report by a short seller sparkeda tumultuous few months that led to the departure of topmanagers, including founder and then-chairman Robert Terry.
As of Thursday's closing price of 89.5 pence, its marketcapitalisation was about 398 million pounds. The stock hadearlier in the day fallen to 75 pence, its lowest in nearly sixmonths.
The Serious Fraud Office said on Wednesday it had opened acriminal investigation into business and accounting practices atQuindell. The company, under new management, said theinvestigation was related to past practices.
About 36 million Quindell shares were traded on Thursday,four times their daily moving average of 8.5 million over thepast year.
Asked by Reuters via email whether Quindell's investors orcustomers were talking of pulling away support, Stefan Borson,Quindell's general counsel, said: "We are in constant contactwith investors and customers as normal - it is business asusual."
Two of Quindell's biggest shareholders, Fidelity Managementand Research Co and Toscafund Asset Management LLC, did notimmediately respond to emailed questions.
Quindell also posted a 238 million-pound loss for 2014 onWednesday.
Its shares were suspended at the company's request on June24 after Britain's financial watchdog said it had begun aninvestigation into public statements regarding the company'sfinancial accounts for 2013 and 2014.
The company's problems began in April 2014 when short sellerGotham City Research LLC questioned the company's revenue modeland profit quality. Quindell later won a libel suit againstGotham. (http://reut.rs/1IJx3eC)
Gotham City Research did not respond to an emailed requestfor comment on Thursday.
In November, Terry stepped down saying he was "disappointedand sorry" after Quindell disclosed a complex share transactioninvolving the founder and two other directors.
Quindell was one of the most shorted stocks on the LondonStock Exchange with more than 90 percent of shares available toborrow out on loan at the end of last year, according tofinancial information and services company Markit.
Just under 6 percent of the stock available to borrow wasout on loan as of Monday, according to Markit. ($1 = 0.6443 pounds) (Editing by Susan Fenton)
