NEW YORK, Feb 22 (Reuters) - Prices for chocolate-making raw material cocoa rose to fresh peaks on Thursday, accumulating gains above 10% this week alone, amid reports of negative production outlook for the world's second largest grower.

London cocoa futures on ICE exchange surged past the psychological 5,000 pound barrier on Thursday while New York cocoa breached the $6,000 mark, as supply tightness propelled both markets to fresh record highs.

Cocoa prices in London closed 1.7% up to 5,062 pounds per metric ton, after earlier hitting a peak at 5,100 pounds. Futures in New York ended little changed at $5,860, after reaching a record at $6,020/ton.

The fresh price peaks came amid news that cocoa production from Ghana for the 2023/24 season is expected to be almost 40% below a target of 820,000 metric tons, two sources from the country's sector regulator COCOBOD said.

A drop of that magnitude would put cocoa output at around 500,000 tons, significantly below the median forecast in a Reuters poll issued earlier this month of 620,000 tons.

Analysts believe the high prices - London cocoa rose 70% last year and gained 50% so far in 2024 - will start to impact demand as chocolate makers plan to raise prices for their products to cover higher raw material costs.

Changing formulations of products to use less cocoa was also a possibility for food companies, they said, although chocolate giant Nestle on Thursday played down the move.

"We have a long history in cocoa and cocoa flavored products... tinkering with recipes and flavor profiles because cocoa prices have gone up would be, in my opinion, a mistake," said Nestle Chief Executive Mark Schneider.

"It's just one more commodity cost variation that we have to deal with," he said.

In other soft commodities, raw sugar prices rose 0.26% to 22.83 cents per lb after hitting more than a one-month low of 22.11 cents.

Traders cited falling prices for refined sugar in China as a bearish signal, since it cuts into refiners' margins and can make imports non-economical.

London refined sugar fell 0.92% to $619.70 per ton.

Robusta coffee fell 2% to $3,113 a ton, going into the opposite direction of local prices in top grower Vietnam which rose this week on higher exporter demand after the Lunar New Year.

Arabica coffee fell 2.6% to $1.8315 per lb. (Reporting by Nigel Hunt and Marcelo Teixeira; additional reporting by Maytaal Angel and Richa Naidu; Editing by David Goodman, Paul Simao and Shailesh Kuber)