Chinese and Middle East firms are climbing the annual sales ranking of global chemical companies compiled by IHS Chemical Week.

The shake-up in the rankings points to a major leadership change in the global chemical industry, which was once dominated by U.S., European and Japanese firms, according to IHS, publisher of IHS ChemicalWeek.

BASF registered total sales of $81.5 billion for 2013, keeping the German-based chemical producer in top position on the list for the eighth consecutive year.

Chinese company Sinopec and Saudi Arabia's Sabic rose to second and third place, with respective sales last year of $72.3 billion and $60.7 billion. Completing the top five were ExxonMobil with sales of $59.3 billion, and Dow Chemical with $57.1 billion.

"The presence of both Sinopec and Sabic in the top three companies on our sales ranking, which puts them ahead of powerhouse U.S. companies ExxonMobil Chemical and Dow Chemical, respectively, is profound when you realize that just 10 years ago, neither of these companies were in the top-10," commented Rob Westervelt, editor-in-chief of IHS Chemical Week.

In 2000, both Sinopec and Sabic each had chemical revenues of around $7 billion. They have increased that figure by approximately 10-fold in less than 15 years, Westervelt pointed out.

Potentially, either Sinopec or Sabic could overtake BASF within the next few years "because Sabic has the feedstock advantages, and Sinopec has the market advantages that make them formidable competitors," Westervelt suggested.