Britain's JD Sports Fashion has reportedly agreed to buy Finish Line for $558 million according to CNBC. The report states that Finish Line is one of the largest retailers of premium multi-branded athletic footwear, apparel and accessories in the United States, trading from 556 branded retail stores across 44 states and Puerto Rico and online. 

JD Sports has expanded in recent years, gaining a presence in France, Spain, and South Korea, but this will be their first plunge into the U.S. market. Shares in JD Sports reportedly jumped as much as 3.9% in early trading following today's announcement, while Finish Line shares jumped as much as 30 percent to $13.74 in early trading, according to Bloomberg.

"This is a landmark day for JD and will be transformational for the business. It immediately offers a major presence in the U.S., a clear next step to further increase our global scale," its Executive Chairman Peter Cowgill said, according to CNBC.

"The deal looks a sensibly-priced entry point into a market that JD must embrace to be considered a genuinely global player," said Peel Hunt analyst Jonathan Pritchard, who has a "buy" rating on the stock.

The deal, which reportedly requires the approval of both companies' shareholders, is expected to be complete no earlier than June.