The British bank's shares dipped 2 percent on Wednesday after the Wall Street Journal (WSJ) said the bank had an internal team assessing possible targets and is looking for a franchise with a strong branch network and deposit base.
The bank, led by Chief Executive John Varley since 2004, is emerging as one of the winners from the financial crisis and has long looked at opportunistic deals, and analysts and bankers said a U.S. deal could make sense.
It is not in talks with any U.S. banks and no deals are imminent, the WSJ said, citing people close to the matter.
Barclays declined to comment.
It would make sense, and if they do, it would make sense to do it in size, said Mike Trippitt, analyst at Oriel Securities. If ever there was a time to do it, this would be it.
Analysts said there was a long list of candidates as the U.S. industry reshapes, and cited potential targets such as PNC Financial
They are valued at between $10 billion and $30 billion, and analysts said other targets could include Bancorp
Barclays shares were down 0.95 percent at 342.5 pence at 1320 GMT to value the business at about 41 billion pounds ($61 billion), underperforming a flat European bank sector <.SX7P>.
A sizeable deal would likely require a capital raising but attract retail deposits as regulatory reform increases pressure on balance sheets and would be seen as positive, as would distribution for its U.S. credit card products and growing Barclays Capital investment banking business, analysts said.
Barclays bought Lehman Brothers' North American operations in 2008, significantly bulking up BarCap in the country.
Coming on the back of a successful Lehmans deal and Barclays managing its way pretty well through the crisis, now is the right time to be contemplating the next deal, said Simon Willis, analyst at NCB Stockbrokers.
The bank also has over 7 million Barclaycard customers in the U.S. and operates wealth management there. Trippitt estimated 21 percent of Barclays' risk-weighted assets were based in the U.S.
Banks face a raft of regulatory changes, which could prompt Barclays and rivals to search for more retail deposits to avoid reliance on wholesale funding.
The evolving regulatory environment means there's a premium now on a retail deposit base and every bank is chasing deposits, said NCB's Willis.
Barclays is also keen for retail banking to grow to counterbalance BarCap's growth. It wants that unit to represent about one-third of group profits, but that share has jumped after the Lehman deal.
Barclays is expected to continue building up its retail arm in western Europe with small acquisitions adding to organic growth, and has struck deals in Italy, Spain and Portugal.
Asia could be a more attractive market to grab deposits and grow, bankers and analysts said, but valuations there are steep compared to the U.S. and Europe.
In November, Barclays appointed Antony Jenkins as head of a new unit called global retail banking after the surprise ousting of former retail boss Frits Seegers, and Jenkins is reviewing strategy. He oversaw the expansion of Barclaycard in the U.S. in his previous role as head of the credit card arm.
Barclays has a chequered history in the U.S.
It aggressively expanded there in the 1970s and had about 600 offices and branches across 36 states by 1981. But it hit troubles as losses from soured property loans in New York and California and oil and gas ventures contributed to a jump in bad debts, and by the early 1990s it was retreating.
Its profile there has risen after the Lehman deal, and on Thursday Barclays President Bob Diamond will break ground at the Barclays Center, an 18,000-seat sports arena in Brooklyn, New York, that will be home to Nets basketball team.
(Additional reporting by Victoria Howley; Editing by Dan Lalor and Sharon Lindores)