Groupon announced a handful of deals on Wednesday to expand its presence in Silicon Valley and in Asia, as Google Inc remains in talks to acquire the online discount coupon provider.

Google and Groupon are in direct negotiations over a potential merger, a person familiar with the situation said without disclosing the stage of talks. However, there are some concerns over the antitrust scrutiny that a deal would undergo, the source said.

The more Google acquires, the more antitrust issues they are opening themselves up to, said the source, who requested anonymity because the talks are ongoing. That has to be considered.

The review process in the United States will take a long time, said one head of media investment banking, not involved in the discussions.

Groupon said it would not address any speculation about its business, an apparent reference to media reports on Tuesday that the Google was close to buying it for $6 billion.

Chicago-based Groupon said it was acquiring Ludic Labs, which develops local marketing services including Offer Foundry and Diddit. It also announced the opening of an office in downtown Palo Alto, California, and plans to expand its team there from 25 people to more than 100 in the next year.

Late on Tuesday, Groupon said it had acquired three daily deal websites -- uBuyiBuy, Beeconomic and Atlaspost -- to expand its reach across East and Southeast Asia. Atlaspost has more 1.2 million users in Taiwan, Groupon said.

Groupon did not disclose terms of any of the transactions.

The company sends its members daily e-mails with details of discounts for 200 goods and services. The deals are activated only when a minimum number of people agree to make a purchase, giving Groupon the clout to negotiate steep group discounts on products and services.

The three Asian companies, active in Taiwan, Hong Kong and Singapore, will transition to the Groupon brand in a few months.

Groupon also launched Groupon Hong Kong, Groupon Singapore, Groupon Philippines and Groupon Taiwan on Wednesday.

We see enormous potential in the Asian marketplace, President Rob Solomon said in a statement.

Groupon's global network has more than 33 million subscribers in 35 countries.

(Reporting by Nadia Damouni and Martinne Geller in New York and Melanie Lee in Shanghai; Editing by Chris Lewis, Gerald E. McCormick and Lisa Von Ahn)