Global petrochemical prices leveled off in October and are showing signs of picking up, according to the latest monthly report from Platts.

The company’s Global Petrochemical Index (PGPI) reveals that October prices in the $3-trillion-plus global petrochemicals market were virtually flat based on a monthly average, but prices rose slightly when valued on a month-end to month-end basis from September.

This is the first time the markets have shown intermonth gains since May, the energy and metals news provider said.

The PGPI is a benchmark basket of seven widely used petrochemicals: ethylene, propylene, benzene, toluene, paraxylene, low-density polyethylene (LDPE) and polypropylene. In October 2015 the monthly average price was $785 per metric ton (mt), down 41 percent from $1,324/mt in October 2014 but a decrease of just $1/mt from September 2015.

Crude oil prices increased by 2 percent from September to October, while naphtha prices were up 3 percent.

Platts found a mixed picture for olefins prices last month, with ethylene rising 1 percent from September and propylene down 5 percent. Polyethylene and polypropylene, plastics manufactured from ethylene and propylene respectively, closely followed their feedstock price, with global polyethylene prices up 1 percent and polypropylene prices falling 3 percent.

Prices of aromatics — a group of scented hydrocarbons with benzene rings used to make a variety of petrochemicals — were stronger across the board in October. Benzene climbed 4 percent, while toluene gained 2 percent and paraxylene prices rose by 1 percent compared with September.

“Exports of benzene out of Korea were down 30 percent in October, which pinched supplies globally, pushing up prices as did the strengthening of upstream prices of crude oil and naphtha,” explained Jim Foster, head of analysis for petrochemicals and agriculture at Platts.