Vienna  - The price for crude oil produced by the Organization of the Petroleum Exporting Countries (OPEC) rose again slightly on Thursday, reverting a downward movement started at the end of last week, data released by OPEC on Friday show.

One barrel (159 litres) of OPEC-produced crude stood at 129.44 dollars a barrel on Thursday, 0.99 dollars higher compared with 128.45 dollars on the previous day.

Saudia Arabia, the world's largest oil exporter, has invited oil consumers and producers to a summit in Riyadh on Sunday to discuss the causes of spiralling oil prices.

OPEC calculates an average basket price based on 13 important brands produced by cartel members. (dpa)