* Macquarie Capital, Moelis advising on stake sale -sources
* Timing dependent on pricing discussions with regulator
By David French and John Tilak
July 25 (Reuters) - Macquarie Group MQG.AX has chosen Moelis & Co MC.N and its own investment banking arm to advise on the sale of its 42 percent stake in Washington utility Puget Energy, people familiar with the matter said on Tuesday.
The stake, which is worth as much as $4.5 billion and held in a fund belonging to Macquarie's infrastructure business, will be put up for sale later this year, according to two of the sources, who spoke on condition of anonymity as the information is private.
The timetable for the sale is dependent on Puget's discussions with the Washington Utilities and Transportation Commission about the electric and gas prices the utility will charge going forward.
Puget has applied to increase prices to fund upgrades to its infrastructure and other expenses, while the regulator recommended in June that Puget cut charges based on readjusting the value of a coal plant and costs relating to storm damages.
A decision, on what is known as a general rate case, is due by mid-December.
Macquarie and Moelis declined to comment.
Infrastructure businesses, such as utilities, have been highly prized in recent years by investors due to their steady, long-term revenue generation.
Avista Corp AVA.N , another Washington-based electric utility, said last week it had agreed to be sold to Canada's Hydro One HYDRO.UL for $5.3 billion including debt, while Berkshire Hathaway (NYSE:BRKa) BRKa.N and Elliott Management are currently competing to acquire Texas' Oncor Electric Delivery Co TXEFHO.UL for around $18 billion. was part of a consortium including three Canadian pension funds that bought Puget in 2009 for $7.4 billion.
Bloomberg News reported in June that Macquarie was considering selling Puget, whose core business - Puget Sound Energy - is a regulated utility serving 1.1 million electric and 790,000 natural gas customers, primarily in Western Washington state.