Barclays PLC (BCS) said Tuesday that it will buy Citigroup Inc.'s (C) credit card business in Portugal, as it continues to push for expansion outside the U.K.

Barclays is acquiring about 400,000 credit card accounts with gross assets of about EUR644 million, it said.

The bank didn't disclose how much it is paying for the business, but the Wall Street Journal, citing people familiar with the matter, has reported the amount to be less than $100 million.

Barclays currently has more than 130 branches in Portugal, and Frits Seegers, chief executive of Barclays Global Retail and Commercial Banking, said the acquisition will put the bank among the five top credit card players in the country.

"With this acquisition, we will deliver a real step change in our business, significantly increasing Barclays Portugal's customer base and providing extensive cross-sell opportunities," Seegers said.

The bank intends to rebrand existing Citi cards with its global Barclaycard brand "over time."

Earlier Tuesday, Barclays Chief Executive John Varley told a London conference that the goal for the bank's global retail and commercial banking business is to have half of its profit generated from international operations.

In the first half of 2009, businesses outside the U.K. accounted for 18% of the operation's profits.

Barclays has said it will push to expand its business organically and through acquisitions in a time that competitors, particularly those that received government money such as Citigroup, are scaling back.

Earlier Tuesday, U.K. newspaper The Times reported that Barclays was eyeing the banking division of U.K. insurer Standard Life (SL.LN), which could be worth GBP200 million to GBP300 million.

"We are looking at acquisitions in Western Europe," a bank spokesman said. He declined to comment on Standard Life specifically.

Meanwhile, Citigroup, which has been hard hit by the global financial crisis and is now 34%-owned by the U.S. government, is pulling back its presence in the U.S. and abroad.

In a recent presentation, CEO Vikram Pandit classified the bank's Western Europe retail banking and cards portfolios as non-core assets.

"The transaction is in line with Citi's goal to reduce assets, tightly manage risks and optimize the value of assets in Citi Holdings, while working to generate long-term profitability and growth from Citicorp, which comprises its core franchise," Citigroup said in a separate statement.

The sale won't have a material impact on Citigroup's net income, it added.

Barclays' acquisition is subject to competition clearance by Portuguese authorities and is expected to close before the end of the year.

At 1144 GMT, Barclays shares were up 6 pence, or 1.6%, at 371 pence in a slightly lower overall market.

-By Patricia Kowsmann, Dow Jones Newswires. Tel +44(0)207-842-9295, patricia.kowsmann@dowjones.com