BRUSSELS (Reuters) - U.S. grains merchant Bunge and Glencore ( GLCNF )-backed Viterra have offered concessions in an attempt to win EU antitrust approval for their $34 billion merger, an update on the European Commission website showed on Friday.

The companies announced their merger a year ago to rival global giants Archer-Daniels-Midland ( ADM ) and Cargill.

The European Commission, which did not provide details of the concessions in line with its policy, extended its deadline for a decision to Aug. 1 from July 18.

It is now expected to seek feedback from rivals and customers before deciding whether to accept the concessions or demand more. It can also open a four-month long investigation if it has serious concerns.

The deal has triggered concerns from the Canadian competition watchdog and farm groups. It also needs regulatory clearance in North America, South America and China.