* Co valued at about $5.73 bln at highest trading price
* Co backed by Bain Capital, TPG Capital (Adds details; updates share movement)
May 9 (Reuters) - Shares of drug research company QuintilesTransnational Holdings rose as much as 11 percent in itsmarket debut, valuing the company at as much as $5.73 billion.
The Durham, North Carolina-based clinical trials company'sinitial public offerings is the largest among the 11 expected tobe priced this week. The week could see the highest IPO volumesince late 2007, according to market data firm Ipreo.
Other offerings that have been priced this week includethose of residential mortgage company PennyMac FinancialServices Inc and biotech company Receptos Inc.
Quintiles raised $947 million in its IPO, more than planned,as it had priced 23.7 million shares at $40 each, compared withits plan to sell 19.7 million shares at $36 to $40 each.
Quintiles, founded in 1982, is backed by private equityplayers Bain Capital LLC and TPG Capital LP.
They became the lead investors in Quintiles in January 2008after One Equity Partners sold its stake in the company.Britain's 3i Group Plc and Singapore's Temasek Holdingsare also investors in Quintiles.
The company is the largest provider of contract researchservices in the world to biopharmaceutical companies, includingmedical device and diagnostics companies.
Quintiles generated adjusted earnings before interest, tax,depreciation and amortization of $177.5 million on revenue of$4.9 billion in the year ended Dec. 31, 2012.
The company's sales were 70 percent higher than its nearestcompetitor Covance Inc said Morningstar analyst LaurenMigliore in a research report. Covance is valued at about $4.15billion.
Quintiles spent about $135 billion on R&D in 2012, whichwill grow to about $139 billion in 2015, according to theprospectus it filed with the Securities and Exchange Commission.
Of all the new drugs approved between 2004 and 2011,Quintiles helped develop or commercialize 85 percent of thecentral nervous system drugs, 76 percent of the oncology drugs,and 72 percent of the cardiovascular drugs, according toMorningstar.
A recent slowdown in R&D spending did not have an effect onQuintiles' performance as the company focuses primarily on PhaseII-IV clinical trials.
This has saved Quintiles from having to endure the steeppullback in early-stage spending, particularly for animaltesting, toxicology, and preclinical services, that has plaguedother contract research firms.
Quintiles shares were trading up 10 percent at $44.05 on theNew York Stock Exchange on Thursday.
Morgan Stanley, Barclays and JPMorgan are the leadunderwriters to the offering. (Reporting by Tanya Agrawal in Bangalore; Editing by SreejirajEluvangal and Joyjeet Das)