New Delhi, Oct. 20 -- Walmart Inc., the world's largest retailer, is raising at least $2.5 billion through a new US dollar bond offering and exploring its first Canadian-dollar debt sale as it seeks to diversify funding sources amid rising investment requirements.

The company launched a four-tranche US dollar bond offering on Monday, with maturities ranging from three to 10 years, Bloomberg reported, citing people familiar with the matter. The transaction attracted investor demand exceeding $14 billion at its peak.

Pricing for the longest-dated tranche tightened by about 0.3 percentage point from initial discussions to a spread of 0.45 percentage point over US Treasuries, according to the report.

Separately, Walmart has asked Bank of A...