Asia's naphtha crack turned positive for the first time this month on Tuesday, helped by a historic price plunge in oil prices.

The naphtha crack hit a premium of $18.80 a tonne to Brent crude versus a small discount in the previous session. Brent crude is a raw material of naphtha.

India's BPCL sold 30,000 tonnes of naphtha for April 24-25 loading from Mumbai to Gunvor at a discount between a discount of $5 and $9 a tonne to its own formula on a free-on-board (FOB) basis.

The refiner had previously sold a cargo for April 12-14 loading from the same port at a small premium to Total.

BPCL on Monday had also sold another parcel for April 26-27 loading from Kochi to Glencore at premiums of $15 to $20 a tonne to its own price formula on a FOB basis.

It had previously sold a cargo for April 11-12 loading from the same port of Kochi to Total at a premium of about $29 a tonne. Asia's gasoline crack, in contrast to that of naphtha, fell to a discount of $6.01 a barrel to Brent versus a discount of $5.42 a barrel in the previous session.