The cash premium of the benchmark 380-cst fuel oil grade firmed for the fourth straight session on Wednesday, underpinned by lower supply in the region in early April. The 380-cst cash premium rose 76 percent or close to $1 a tonne to a two-week high of $2.22 a tonne, Reuters data showed. this period has provided some support for the 380-cst market. Around 4.17 million tonnes of fuel oil will arrive in April from the West, of which only an estimated 950,000 tonnes or just 20 percent of the total, will make a landfall in the first 10 days of the month, Reuters reported earlier. On the other hand, demand from southeast Asia is also set to increase…