International Game Technology has announced a cross-licensing deal with Scientific Games, the fourth such agreement signed this year and the largest to date.

IGT and Scientific Games are holders of two of the largest slot game feature patent portfolios in the United States, and will now be able to develop games using patented features from each other's portfolios.

Financial terms of the agreement have not been disclosed.

The partnership also allows Scientific Games to use patented features used by other companies that have already signed similar partnerships with IGT.

Earlier this year IGT signed partnerships with Konami Gaming, Aruze Gaming and Incredible Technologies.

It already has agreements in place with other high-profile suppliers including Everi Holdings, Aristocrat Leisure and NetEnt.