UPDATE 1-Northam says output up 14 pct in 4 mts of 2009

* Proceeding with the Booysendal feasibility study

* Output up 14 pct at 3,543 kg in the first 4 mths

* Sales volumes up by 639 kg, revenues at 1.3 bln rand (Adds detail)

JOHANNESBURG, Nov 17 (Reuters) - South Africa's Northam Platinum (NHMJ.J) on Monday reported a 14 percent rise in output in the first four months of the 2009 financial year despite a heavy drop in global commodity prices.

Northam said production of metals in concentrate rose 14.3 percent to 3,543 kg (113,910 ounces) in the four-month period, and sales volumes increased by 639 kg, with revenues amounting to 1.3 billion rand ($128.7 million).

Northam's 2009 financial year ends in June.

The company also said the average metal price for the platinum group rose 24 percent compared to the same period the previous year to 359,844 rand per kg or $1,391 per ounce.

Northam said it was proceeding with the feasibility study for its recently acquired and vast Booysendal mine, scheduled to be completed in the third quarter of 2009.

"Initial indications that that Booysendal project will follow a modular production ramp-up approach remain unchanged," it said in a statement.

"The estimated cost for the current financial year is 50 million rand of which 24 million rand has been spent to date."

The company said it would continue to cover its cash costs and capital expenditure, should the rand and spot market prices stay around current levels.

(Reporting by James Macharia and Agnieszka Flak)