MILAN, Dec 23 (Reuters) - Italy's antitrust watchdog has opened an investigation into the business relationship between Telecom Italia (TIM) and FiberCop, the fixed-line network company spun-off from the former phone monopoly.

After the 22 billion euro ($22.90 billion) sale of FiberCop to a consortium led by U.S. investment fund KKR last July, TIM signed a 15-year master service agreement $(MSA)$ to regulate business with its former network company, which offers connectivity capacity to TIM and rivals operating in the Italian telecoms market.

TIM's contract with the operator of its former fixed-line fibre and copper network "contains provisions that could result in an anti-competitive agreement", the competition authority said on Monday.

TIM declined to comment on Monday. It has previously said that the contract meets regulatory standards. A FiberCop representative was not immediately available to comment.

($1 = 0.9607 euros)

(Reporting by Cristina Carlevaro and Elvira Pollina Editing by David Goodman)

((cristina.carlevaro@thomsonreuters.com; +39 06 80307729;))