BRUSSELS, July 12 (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.