LONDON (Reuters) - Gold miner Centamin (CEY.L) has made a drastic cut to its full-year production guidance and raised its cost expectations because of lower-grade ore at its Sukari mine in Egypt, sending its shares lower.
Centamin's London-listed shares sank as much as 15 percent to their lowest since Dec. 13 at 135 pence.
Canaccord Genuity analysts said the 2018 guidance revisions was negative but in line with their expectations.
Gold output in 2018 will now be between 505,000 and 515,000 ounces, compared with a previous forecast of 580,000 ounces, Centamin said in a production update on Friday.
Centamin's all-in sustaining cost of producing an ounce of gold, an industry benchmark, is now projected at between $875 and $890 an ounce. Its previous target was $770.
Canaccord Genuity analysts said the 2018 guidance revisions were negative but in line with their expectations.
Centamin said there was low-grade ore from the transitional zone in Sukari's open-pit operation and lower development grade from underground.
Underground production is about 10 percent below forecast due to lack of equipment availability, Centamin said, while open-pit tonnage was ahead of schedule, albeit at a lower grade.
An updated mine plan forecast a weaker second quarter but strengthening for the rest of the year, the company said.
It had previously maintained its outlook for the year after posting a twofold increase in first-quarter profit on higher gold output.
"The company has in recent years rebuilt its reputation to one for reliability, so it is disappointing to see such a substantial downgrade just three weeks after it reaffirmed its previous guidance," Investec analysts said in a note.
However, Investec maintained its "buy" recommendation on Centamin, citing the miner's resilient balance sheet, good shareholder returns and long-life production base.
(Reporting by Zandi Shabalala; Editing by David Goodman)