LIMA, May 16 (Reuters) - Shares in Peru's largest construction company Grana y Montero plunged more than 10 percent on Tuesday after prosecutors filed charges against the firm and a former top executive in a corruption case linked to Brazilian builder Odebrecht.
Prosecutors presented the case to the office of Peru's attorney general late on Monday, naming Grana and two other junior partners in a highway project awarded to Odebrecht, which has admitted to paying about $20 million in bribes to win the contract and said the junior partners were aware of the scheme.
At Noon (1700 GMT), Grana y Montero's Lima-listed shares were down 13.3 percent at 2.08 soles ($0.6384), while the company's U.S.-listed depository receipts were down 12.1 percent at $3.21.
In a statement on Tuesday, Grana said the charges "do not change the company's legal situation," as the prosecutors' petition would still need to be evaluated by the attorney general's office before moving forward.
"As we've said on many occasions, the company is totally open to cooperating with the investigations," the statement said.
Grana has previously denied knowing about Odebrecht's kickback schemes in Peru and has said an independent company would conduct an internal probe into dealings with Odebrecht.
The Brazilian builder has admitted to paying bribes in a dozen mostly Latin American countries and has reached cooperation agreements with prosecutors in several governments, widening the reach of the graft scandal.
The charges are a setback for Grana, which had been named to MSCI's emerging market equities index on Monday. ($1 = 3.2580 soles) (Reporting by Ursula Scolla and Luc Cohen; editing by Grant McCool)