Partners Group Holding AG (SWX:PGHN) is considering the sale of some of its infrastructure assets with a combined value of more than $5 billion as the Swiss buyout firm seeks to take advantage of investor appetite in the sector, according to people familiar with the matter. The firm is speaking with advisers as it looks at potential options including a sale of Gren, a Northern European energy company providing services such as district heating, industrial energy and energy-to-waste, people familiar with the matter said, asking not to be identified as the matter is private. Gren could be valued at about ?1.5 billion ($1.6 billion) in a sale though no formal process has kicked off yet, the people said.