UPDATE 1-Generic drugmaker Mylan trims forecast as FDA approval drags

* Cuts top end of FY revenue forecast to $8.0 bln from $8.2 bln

* Cuts top end of FY earnings forecast to $3.45/shr from $3.60/shr

* Plans to launch key generic drugs in fourth quarter

* Shares down 1 pct in premarket trading

(Adds details, background, share price)

Aug 7 (Reuters) - Mylan Inc shaved the top end of its full-year revenue and earnings forecasts, citing delays in approval from the U.S. Food and Drug Administration for key generic drugs that it plans to launch this year.

The company's shares fell 1 percent to $47.40 before the bell on Thursday.

Despite delays in FDA approval, Mylan said it planned to launch a generic version of Teva Pharmaceutical Industries Ltd's multiple sclerosis treatment, Copaxone, in the fourth quarter.

The company also plans to launch a generic version of Pfizer Inc's blockbuster Celebrex, an anti-inflammatory treatment for arthritis, in the fourth quarter.

"Given the anticipated launches of key products ... the fourth quarter is expected to be the strongest quarter of the year," Mylan said in a statement.

However, the company cited "ongoing delays in approvals of key products" as having weighed on its results for the second quarter ended June 30.

Mylan forecast full-year 2014 revenue in a range of $7.8 billion to $8.0 billion and earnings of $3.25-$3.45 per share, a forecast that includes the fourth-quarter launch of generic Copaxone and Celebrex.

It had earlier forecast full-year revenue of $7.8 billion to $8.2 billion and earnings of $3.25-$3.60 per share.

Analysts on average expect full-year 2014 earnings of $3.37 per share on sales of $7.7 billion.

Mylan said its acquisition of Abbott Laboratories' branded specialty and generics business in developed markets outside the United States could help it reach its 2018 earnings target ahead of schedule.

The $5.3 billion deal, announced in July, will bolster Mylan's product line and cut its tax bill.

Canonsburg, Pennsylvania-based Mylan posted a second-quarter adjusted net profit attributable to shareholders of $273.3 million, or 69 cents a share - a penny shy of the average analyst estimate.

Revenue rose 8 percent to $1.84 billion.

Mylan's stock closed at $47.92 on the Nasdaq on Wednesday.

(Editing by Kirti Pandey)