US retail giant Federated Department Stores is to buy rival May Department Stores for $11bn (£5.7bn).
Federated owns world famous stores such as Macy's
The deal will bring together famous stores like Macy's, Bloomingdale's and Marshall Field's, creating the largest department store chain in the US.
The combined firm will operate about 1,000 stores across the US, with combined annual sales of $30bn.
The two companies, facing competition from the likes of Wal-Mart, tried to merge two years ago but talks failed.
Sources familiar with the deal said that negotiations between the two companies sped up after May's chairman and chief executive Gene Kahn resigned in January.
As part of the deal, Federated - owner of Macy's and Bloomingdale's - will assume $6bn of May's debt, bringing the deal's total value to $17bn.
Directors at both companies have approved the deal and it is expected to conclude by the third quarter of this year.
May has struggled to compete against larger department store groups such as Federated and other retailers such as Wal-Mart.
Federated expects the merger to boost earnings from 2007 but the deal will cost it $1bn in one-off charges.
"We have taken the first step toward combining two of the best department store companies in America, creating a new retail company with truly national scope and presence," said Terry Lundgren, Federated's chairman.
Some analysts see the merger as a rescue deal for May.
"Without this deal May would have been, to put it bluntly, washed up," said Kurt Barnard, president of Barnard's Retail Consulting Group.
Federated has annual sales of $15.6bn, while May's yearly sales are $14.4bn.