TGBP provides international payments services to 35,000 business clients, including over 500 financial institutions. Projected 2011 revenues for the unit are approximately £150 million.

Western Union says the acquisition will further its ambitions to expand beyond remittances and stake a claim in the $24 billion international business payments market.

Hikmet Ersek, president and CEO of Western Union, says: "The acquisition of Custom House in 2009 gave us an entry into the business-to-business cross-border payments market, and Travelex Global Business Payments provides us immediate scale, further reach, and added capabilities."

Revenue for the combined business is expected to grow at an initial 10% CAGR over the next three years, with accelerated longer-term growth and margin expansion opportunities once integration activities have been completed.

Integration expenses are estimated at approximately $70 million over two years, yielding annual savings of $30 million.

The transaction is expected to close in late 2011.