UPDATE 1-Amkor Q3 profit doubles, sees strong Q4 rev

* Q3 EPS $0.31 vs $0.15 yr ago

* Rev falls 14 pct

* Sees Q4 EPS $0.17-$0.23

Oct 27 (Reuters) - Amkor Technology Inc's (AMKR.O) third-quarter profit more than doubled, helped partly by a drop in operating expenses, and it forecast a strong fourth quarter.

The microchip packaging and testing company forecast fourth-quarter earnings of 17 cents to 23 cents a share on flat revenue, plus or minus 2 percent, sequentially.

Analysts were expecting earnings of 16 cents a share, before items, on revenue of $592.2 million, according to Thomson Reuters I/B/E/S.

The company, whose customers include Altera Corp (ALTR.O), Atmel Corp (ATML.O), Texas Instruments Inc TXN.N and LSI Corp (LSI.N), forecast fourth-quarter gross margins of 23 percent to 25 percent.

For the third quarter, Amkor earned $81 million, or 31 cents a share, compared with $29.2 million, or 15 cents a share, a year ago.

Revenue dropped 14 percent to $616 million.

Analysts were expecting earnings of 19 cents a share on revenue of $603.5 million.

Operating expenses fell 10 percent to $66.8 million.

Shares of the Chandler, Arizona-based company were up 1 percent at $6.83 in trading after the bell. They closed at $6.74 Tuesday on Nasdaq. (Reporting by Manasi Phadke in Bangalore; Editing by Unnikrishnan Nair)