(Reuters) -- The U.S. Federal Trade Commission is likely to delay a decision on approving Staples Inc's $6.3 billion takeover of rival Office Depot Inc, the Wall Street Journal reported on Wednesday.

The companies and the FTC have been in talks about extending the timeline for approving the deal in the United States after EU regulators launched an investigation last month, the WSJ reported, citing people familiar with the matter. 

Staples shares rose 2.7 percent to $12.70 in afternoon trading, while Office Depot shares rose 2 percent to $6.69.

Staples declined to comment on the report. The FTC and Office Depot were not immediately available for comment.

The European Commission has said that the proposed deal could hurt business customers with international contracts in Europe and those with national contracts in the Netherlands and Sweden due to the risk of price increases. It will decide by Feb. 10 whether to clear or block the deal.

Staples first tried to buy Office Depot in 1996, but the deal was blocked by U.S. regulators in 1997.

The companies said on Aug. 28 this year that they had submitted additional information to the FTC and had agreed to not close the transaction for at least 45 days.

The proposed deal has been approved by competition authorities in China, Australia and New Zealand.

(Reporting by Ramkumar Iyer in Bengaluru; Editing by Shounak Dasgupta and Kirti Pandey)