(Reuters) - Mylan NV <MYL.O> has declined a U.S. Senate committee request to testify about a $465 million pending settlement to resolve charges the company underpaid government healthcare programs by misclassifying its the EpiPen emergency allergy treatment.

In a Nov. 18 letter to the Senate Judiciary Committee released on Monday, Mylan said the company would not attend since government agencies had also refused to testify.

Senator Chuck Grassley, who chairs the committee and had scheduled the hearing for Nov. 30, said in a statement on Monday that Mylan was "ducking responsibility."

Mylan has come under fire for raising the price of a pair of EpiPens to $600 from $100 in 2008 and listing it with Medicaid as a generic product even though it is listed with the U.S. Food and Drug Administration as a branded product. Companies pay smaller rebates to Medicaid for generics.

Following months of Congressional scrutiny, Mylan in October announced a settlement with the Justice Department.

The settlement has not yet been executed, however.

"This seems to contradict Mylan's claim that all potential liability claims have been resolved," Grassley said.

Officials at the Justice Department and the Centers for Medicare and Medicaid Services, which administers Medicare and Medicaid, have declined to testify at the hearing.

Grassley may reschedule the hearing and has the power to issue subpoenas, Jill Gerber, a spokeswoman for Grassley, said in an email. The authority is rarely used and would require a vote or the unanimous consent of the committee, she added.

"One way or another, I intend to get answers for patients and taxpayers," Grassley said in the statement.

Separately, Grassley wrote on Monday to the Securities and Exchange Commission encouraging it to investigate, if it was not already doing so, whether Mylan misled investors when it announced its settlement with the Justice Department.

He asked the SEC to let the committee know by Nov. 29 whether it was investigating.

The SEC declined to comment. A Mylan spokeswoman did not immediately respond to a request for comment.

(Reporting by Toni Clarke in Washington; Editing by Richard Chang)