By Lewa Pardomuan

SINGAPORE, July 30 (Reuters) - Thai raw sugar premiums are likely to stay at the highest in two years this week on tightening supply after the end of the crushing season, but more cane arrivals from rival Brazil may weigh on prices in coming weeks, dealers said on Monday.

Among other commodities, hopes the United States and the European Union will launch new measures to boost their fragile economies could lift Tokyo rubber futures, while rising coffee supply in Indonesia may put pressure on differentials.

Thai high polarisation, or hipol, raw sugar is being offered at premiums of up to 320 points to New York's October contract, which is also partly due to recent high demand ahead of the Muslim Ramadan fasting month.

Thailand, the world's second-largest exporter after Brazil, is expected to ship out a record 7.9 million tonnes of sugar in 2012. The 2011/12 crushing season ended in May, producing a record output of 10.2 million tonnes.

"The physical market seems pretty slow out. Sellers of Thai raws have got the luxury of sitting and waiting - there isn't a lot left," said Tom McNeill, director of Green Pool, a commodities analyst based in Brisbane.

"(But) the physical values in Brazil have been falling quite sharply. There looks to be good availability of raw sugar coming on line."

Brazilian raws are at premiums of 15 to 20 points to futures as more supply entered the market after Brazil's centre-south cane mills kicked into high gear in early July on receding rains -- producing more sugar and ethanol than a year before for the first time this season.

"It would appear the physical supply situation is going to get a little better in the short-term, and Ramadan buying is finished. That is now giving sugar buyers a bit of respite," said McNeill at Green Pool.

In the rubber market, the most active contract on Tokyo Commodity Exchange, January 2013, could find support at 230 yen a kg this week, having plunged to its weakest in more than two years at 222.4 yen last week.

"I think I am more bullish for this week. I am looking at the range of 230 to 250 yen," said Ker Chung Yang, an investment analyst at Phillip Futures in Singapore.

Tokyo rubber futures set the tone for physical prices, but the contracts are often influenced by macroeconomics. Traders are still waiting for fresh measures from top producer Thailand to help prevent prices from falling further.

Thailand approved a 15 billion baht ($475 million) budget in January to buy rubber from farmers to push up unsmoked rubber sheet (USS3) prices to above 120 baht per kg.

But USS3 prices have stubbornly stuck around the 90-baht level in line with global prices, which have been weighed down by fears of weakening demand due to the global economic slowdown.

COFFEE, COCOA

Indonesian robustas could be offered at a discount to London futures this week as the harvest reaches its peak in the main growing island of Sumatra. The grade 4, 80 defect beans were quoted at London levels last week.

In the cocoa market, butter ratios are likely to hover around 1.10 times London futures <0#LCC:> as grinders hold back on sales in an effort to support prices, while hoping to sell more powder to chocolate makers.

When cocoa beans are processed they produce roughly equal parts butter and powder. Butter is a key ingredient for making chocolate, providing its melt-in-the-mouth texture. Powder is used to make chocolate-flavoured products including baked goods, beverages and ice cream.