Shares in C&C surged to €3.83 on the back of the news yesterday morning before falling back to €3.60 in afternoon trading.
The deal will affect 57 workers here. It is expected to close in June and is subject to shareholder approval.
Among the brands that will be sold are the Irish Mist and Tullamore Dew whiskeys.
The division's management team and employees will transfer to the new owner and William Grant will operate C&C's packaging facility in Clonmel, Co Tipperary.
C&C intends to use the proceeds of the sale for debt reduction and to invest in the cider-led long alcoholic drinks (LAD) business. The group owns Bulmers cider and this is expected to become a focal point for the company going forward.
Stephen Glancey, chief operating officer for C&C, believed the sale was best for all concerned.
"While the spirits and liqueurs division has been a successful component of the group for several decades, we believe that William Grant is best placed to grow and develop this business long-term," he said.
Stella David, chief executive of William Grant & Sons, was delighted with the deal.
"We have been looking to further develop our non-Scotch portfolio . . . and C&C's spirits business provides a unique opportunity to . . . enter the highly desirable and dynamic Irish whiskey category," she said.
Grant said it was committed to building a strong business in Ireland and to maintaining and developing current operations across its Irish sites.
News of the sale was welcomed by the markets.
The sale had long been anticipated but the expected price had been in the region of €200m. Liz Hartley, an analyst with Citigroup, thinks the sale is a good deal for C&C.
"We expect the shares to react positively to this news. On a long-term view, we are positive on C&C," she said.
"It considerably strengthens the balance sheet and mediates concerns of refinancing risks," she added.
Liam Igoe at Goodbody Stockbrokers took a similar view. "This is positive news. The disposal vastly improves the company's balance sheet," he said.
"The deal makes C&C a much more focused business, concentrating on the long drinks market in Ireland and the UK.
"The balance sheet strength increases the company's flexibility in terms of potential opportunities that may arise over the next 12-18 months," Mr Igoe added.