(Reuters) - Generic drug maker Mylan NV MYL.O on Wednesday said it disagrees with the reasoning behind the U.S. Food and Drug Administration's decision not to approve its generic for GlaxoSmithKline Plc's GSK.L blockbuster Advair in March.

Mylan President Rajiv Malik said the FDA was asking it to comply with standards set out in draft guidance the agency issued, but that it believes it is not required to do so. An FDA spokeswoman declined to comment, saying she was prohibited by law from discussing a pending application.

Mylan made the comments while reporting first-quarter earnings, in which it flagged declining sales for emergency allergy treatment EpiPen but said it will still meet previously announced earnings targets for the year.

Malik said the company could not comment further on the length of the delay for approval until it meets with the FDA to discuss their disagreement, but that the FDA had designated it as requiring a “major” amendment to its application.

A “major” amendment means a delay of 10-months for an FDA response, according to agency guidelines.

Hikma Pharmaceuticals HIK.L also has a generic version of Advair which is awaiting an FDA decision by May 10. Analysts on Wednesday said they were now expecting the FDA to question that application as well.

Mylan shares fell 0.8 percent to $37.73 in afternoon trading.

The company still backed its full year profit and revenue forecast, despite the delay for generic Advair.

The company said earlier this year that its projections always account for possible delays and rejections.

“It’s sort of a ‘Trust me, we have other stuff that will make up for it,’” said Wells Fargo analyst David Maris. “This is a really big product so I don’t know what that could be, but they did mention Copaxone, and that would be an upside surprise.”

Mylan had originally targeted a 2013 launch for its generic version of Teva’s multiple sclerosis drug Copaxone, but it was delayed. It now expects to hear from the FDA next month.

Mylan reported a first-quarter profit that edged past expectations, helped by demand for products it gained through the acquisition of Swedish drugmaker Meda.

Mylan has come under fire for sharply increasing the price of EpiPen and classifying the life-saving treatment as a generic rather than a branded product, which led to much smaller rebates to state Medicaid programs.

The company said first-quarter sales of EpiPen in North America declined due to increased competition and the launch of its authorized generic, which costs $300.

Mylan posted net income of $66.4 million, or 12 cents per share in the first quarter, up from $13.9 million, or 3 cents per share, last year.

Excluding one-time items, Mylan earned 93 cents per share, beating analysts’ average estimate by 1 cent, according to Thomson Reuters I/B/E/S.