- Shares in Avocet Mining [LON:AVM] fell despite pre-tax profits from continuing operations rising to $20.8m in the three months to the end of March - up from $12.6m a year ago.

Gold production fell to 38,296 ounces in the quarter - down from 47,963 oz last time.

But the average realised gold price increased to $1,543 per oz - up from $1,172 per oz a year ago.

Chief executive Brett Richards said: "Avocet has continued to deliver on its targets as the company makes progress in becoming a leading West African gold mining and exploration company.

"The quarter's operational and financial performance at Inata were in line with guidance to the market and the remainder of 2012 looks encouraging, with cost cutting initiatives and operational efficiency projects expected to produce results during the second half of the year.

"The expansion study at Inata is progressing well and subject to a satisfactory outcome, we anticipate entering construction in late 2012 withcommissioning and firstgold in late 2013."

Randgold Resources [LON:RRS] was another faller.

The company reported a robust performance for the first quarter despite the challenges presented by a coup in Mali, the expansion of its Loulo complex and the stabilising of its new Tongon mine in Côte d'Ivoire.

Profit of US$104m was up 126% on the corresponding quarter in 2011 while production of 165 443 ounces increased by 19% year on year.

However, in line with guidance, both figures were down by 28% and 13% respectively on the previous quarter's record results.

Group operating costs of US$667/oz were in line with those of the previous year, and the cash on the balance sheet of US$457m remained substantial despite significant capital expenditure during the quarter.

Antofagasta's [LON:ANTO] copper output totalled 162,900 tonnes in the first quarter - 25.5% up on a year ago when Esperanza was starting production.

But output was 12.9% lower than the previous three months, mainly due to planned maintenance and expected lower grades at Los Pelambres and lower throughput at Esperanza in February and March as a result of damage to the feed conveyor which has since been repaired.

Gold production totalled 63,500 ounces compared with 22,100 ounces a year ago also reflecting the greater contribution from Esperanza.

· Forecast 2012 production for Esperanza is expected to remain within the range of 160,000 to 175,000 tonnes of copper and 240,000 to 260,000 ounces of gold announced earlier this year, albeit at the lower end of these ranges.

Expected production levels at the other three mines remain in line with the previous forecast.

Molybdenum production at Los Pelambres was 3,100 tonnes in Q1 2012, 19.2% above the previous quarter, mainly due to higher grades.

The sector's biggest riser was Thor Mining [LON:THR] - up by over 12% in late afternoon trading - while the biggest faller was UK Coal [LON:UKC] - down by nearly 9%

At 4:16pm:

[LON:AMI] American Investment Trust share price was -3p at 472p

[LON:ANTO] Antofagasta share price was -50.5p at 1108.5p

[LON:AQP] Aquarius Platinum share price was -1.55p at 129.95p

[LON:AVM] Avocet Mining share price was -8.45p at 161.05p

[LON:BEM] share price was -0.25p at 14.13p

[LON:BKY] share price was +1.5p at 26.5p

[LON:CEY] Centamin Egypt Ld share price was -0.32p at 67.58p

[LON:CHL] share price was -0.12p at 13.38p

[LON:CZA] share price was +0.13p at 51.88p

[LON:FDI] Firestone Diamonds share price was -0.25p at 7.13p

[LON:FRES] share price was -11p at 1558p

[LON:GEMD] share price was +7.8p at 253.9p

[LON:HOC] share price was -0.3p at 479.6p

[LON:KMR] Kenmare Resources share price was -1.12p at 50.28p

[LON:RRS] Randgold Resources share price was -237.5p at 5112.5p

[LON:THR] share price was +0.19p at 1.7p

[LON:UKC] UK Coal share price was -1.75p at 18.25p

[LON:VED] Vedanta Resources share price was -31p at 1175p

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