Oil producer Afren's first-quarter output below target

(Adds details, analyst comments; updates share movement)

LONDON, May 20 (Reuters) - London-listed oil explorer Afren (Berlin: A2J.BE - news) Plc reported first-quarter net production of 35,465 barrels of oil per day (bopd), lower than its target of 40,000 bopd this year.

Shares in the company fell as much as 6 percent in morning trade, making the stock the top percentage loser on the FTSE-250 Midcap Index.

"We see the results on the negative side," Oriel Securities analyst Dragan Trajkov said in a note to clients.

Afren (LSE: AFR.L - news) , which is targeting double-digit production growth over the next five years, has its main assets in Nigeria, but it also operates in Kenya and Kurdistan.

The company also reported a 30 percent fall in first-quarter sales revenue due to a reduced share of production and liftings from its Ebok field in Nigeria and lower realised average oil prices.

Revenue from continuing operations fell to $269 million from $386 million a year earlier.

Average net production at Ebok - its main producing asset - fell to 25,971 bopd down from 33,513 bopd a year earlier.

The oil explorer and producer said analysis of 3D seismic data of its Ogo oil field - the world's third largest discovery of 2013 - would begin shortly.

"At first glance the (first-quarter) update appears to be in-line. However, factoring in the payments to field partners drives a reduction in our valuation, making the shares less attractive," Canaccord Genuity (Other OTC: CCORF - news) analysts said in a note and downgraded the stock to "hold" from "buy".

Shares in Afren were trading down 5 percent at 146.4 pence at 0910 GMT on the London Stock Exchange (Other OTC: LDNXF - news) . (Reporting by Karolin Schaps and Roshni Menon; Editing by Gopakumar Warrier)