(Reuters) - Salesforce.com Inc and Slack Technologies Inc have received requests for additional information from the antitrust division of the U.S. Department of Justice related to their $27.7 billion merger, regulatory filings showed on Tuesday. The two companies were also asked to provide documentary material, the filings here showed. On Dec. 1, cloud computing company Salesforce.com agreed to buy the workplace messaging app as it bets on an extended run for remote working and sharpens its rivalry with Microsoft. The deal is still expected to be completed during the fiscal quarter ending July 31.