Wagners Holding Co Ltd has suspended the supply of cement to Boral Ltd for six months after Boral had issued a third-party pricing notice to Wagners under their cement supply agreement.

Boral has seen that it can obtain cement supplies cheaper than the price Wagners is offering. Boral's market price is in the form of an unsigned offer and Wagner's believe it may not be genuine.

Wagners has commenced a formal process to disrupt the validity of the action, says Proactive Investors. Wagners has said that the pricing would cost around US$20m in revenue in the event of supply suspension for six months.