(Corrects to Praxair's management in 2nd para)
* Fund backs proposed $74 billion deal
* Held 4.76 pct stake in Linde, 1 pct in Praxair end-2016
* Fund value tops $1 trillion milestone
OSLO, Sept 19 (Reuters) - The proposed $74 billion tie-up of German industrial gases group Linde and U.S. peer Praxair got a boost on Tuesday when the world's biggest sovereign wealth fund said it was backing the deal.
The Norwegian fund, which also said the value of its assets had topped $1 trillion, will vote in favour of four key resolutions proposed by Praxair's management at a Sept. 27 meeting of shareholders, it said.
"We support the strategic rationale for the merger ... the proposed business combination is in the best long-term interest of Linde AG shareholders," Norges Banks Investment Management (NBIM), which manages the fund, said in a statement.
NBIM, which only discloses the size of its individual holdings once per year, owned 4.76 percent of Linde's shares at the start of 2017, worth $1.46 billion, and 1.0 percent of Praxair, valued at $335.6 million.
"We seek to provide clarity and avoid any potential market speculation about our voting decision," it said. "Norges Bank Investment Management has tendered all shares held in Linde AG in connection with the business combination."
The value of the Norwegian fund, which owns about 1.3 percent of all globally listed equities and also has large positions in fixed income and real estate, has hit $1 trillion, NBIM confirmed.
A Reuters calculation, based on the fund's own live valuation on its website, showed the fund hit the trillion-dollar mark on Sept. 12.
Established to save oil and gas revenues for future generations, the fund is now worth about 2.5 times Norway's annual gross domestic product, against original projections it would peak at 1.3 times GDP in the 2020s.
"I don't think anyone expected the fund to ever reach $1 trillion when the first transfer of oil revenue was made in May 1996," said NBIM Chief Executive Officer Yngve Slyngstad.
"Reaching $1 trillion is a milestone, and the growth in the fund's market value has been stunning," he added.
The milestone was reached partly thanks to a rise in the fund's dollar value in recent months caused by the dollar's own decline against other major currencies.
Measured in Norwegian crowns, the fund stands at 7.81 trillion, below the 8 trillion crowns it hit in April. (Reporting by Terje Solsvik; Editing by Nerijus Adomaitis and Mark Potter)