Alimentation Couche-Tard (ACT) has withdrawn its proposal to acquire Seven & i Holdings due to “a lack of constructive engagement by Seven & i,” ACT said in a press release.

Seven & i said it “confirms that ACT has unilaterally decided to end discussions and withdraw its proposal to acquire the Company,” in a separate press release.

The announcement comes after a year of negotiations.

In a letter to Seven & i’s board, Couche-Tard accused Seven & i of a “calculated campaign of obfuscation and delay.” Seven & i said in a statement that it would accept Couche-Tard’s decision, though it found the announcement “regrettable.”

The Japanese retailer defended its actions, saying the ACT letter contained “numerous inaccurate statements” and that its special committee had engaged in “sincere and constructive discussions.”

“The battle for control of 7-Eleven has been widely watched as a barometer of the sweeping changes underway in corporate Japan. …For much of the past decade, Seven & i had been at war with activist investors from the United States who argued it would be worth more if it focused solely on its core convenience stores and sold off its struggling peripheral businesses. That agitation had spurred little action,” wrote The New York Times.

Previously in the saga, in March ACT said it would continue its friendly pursuit of Seven & i. ACT’s top executives, including founder and executive chairman Alain Bouchard, CEO Alex Miller and CFO Filipe Da Silva, visited Tokyo in March to speak with media about its $47 billion bid to buy Seven & i.

In April, ACT said it “signed a non-disclosure agreement with Seven & i to progress transaction discussions, facilitate due diligence and collaborate on plans to engage with regulators.” This was announced as the companies were reportedly taking steps to divest thousands of stores they collectively own in North America to ease regulatory concerns ahead of a potential merger.