CSR (ASX:CSR) is disappearing with its French suitor, Saint-Gobain, striking a formal deal to make a bid at $9 a share.

CSR had its shares suspended on Monday to allow for an important announcement which came at 5:49 pm with the news of the formal offer.

Saint-Gobain said on Monday it had agreed to buy CSR for $A4.30 billion in cash in a scheme of arrangement deal aimed at increasing its exposure to the Asia-Pacific. The French construction-materials company said it had entered into a definitive agreement to buy CSR with an offer of A$9.00 a share.

The bid represents an enterprise value of $4.5 billion, including debt and at least A$1.3 billion in property value that could be monetized, Saint-Gobain said.

The companies revealed last week that they were in talks.

Saint-Gobain's board unanimously approved the combination, while CSR's board recommended that its shareholders vote in favor of the deal, Saint-Gobain said.

The deal is expected to be closed in the second half of the year.

Saint-Gobain said it expects the deal to help its earnings per share from the first year and that the transaction will increase the company's exposure to Australia's high-growth construction market.

CSR said that it had also agreed with Saint-Gobain that a fully franked dividend may be paid to shareholders, with the amount of that dividend deducted from the cash offer price.

"Additionally, a 2 cents per month ticking fee, accruing on a daily basis, will be payable if the effective date of the Scheme is delayed beyond 26 June 2024, which would not be deductible from the cash offer price," CSR revealed.