WELLINGTON, July 20 (Reuters) - New Zealand's Fletcher Building...

WELLINGTON, July 20 (Reuters) - New Zealand's Fletcher Building Ltd (FBU) cut its earnings guidance on Thursday and said chief executive Mark Adamson will leave the business.

The company said its operating earnings are expected to be approximately NZ$525 million, down from a previous guidance of NZ$610-$650 million. It follows an earnings downgrade in March, and the same cost overruns are the cause, Fletcher said in a statement.

"I am disappointed to finish my tenure on the back of a challenging result in the Construction Division, however I am proud of what has been achieved over the last five years," Adamson said in the statement.

Francisco Irazusta will take over as interim CEO, effective from July 24, and the company will start a process to appoint a new CEO, it said.