FILE PHOTO: A general view of the Norwegian central bank in Oslo, March 6, 2018. Picture taken March 6, 2018. REUTERS/Gwladys Fouche/File Photo

OSLO (Reuters) - U.S. financial regulators should improve the transparency of so-called proxy votes to ensure shareholders’ views are properly reflected, the managers of Norway’s $990 billion sovereign wealth fund, the world’s biggest, said on Monday.

The fund, which invests the proceeds from Norway’s oil and gas industry in foreign bonds, real estate and equities, currently owns around $250 billion worth of equities in the United States.

As thousands of shareholder meetings are held each year, Norges Bank Investment Management (NBIM) and other large institutional investors often rely on custodians and proxy advisers as intermediaries to vote on their behalf.

While individual investors retain the right to decide which way to vote on resolutions, it’s often difficult to know whether their instructions have been respected, NBIM said in a letter to the Securities and Exchange Commission (SEC).

“This prevents investors from verifying that intermediaries have respected their direction and that the company has taken their vote into account,” NBIM said.

“Introducing a mandatory requirement for all intermediaries to transmit the necessary information throughout the voting chain, to provide transparency to shareholders on how their votes have been cast, would help address this issue,” it added.

NBIM frequently voices its opinions on matters of financial regulation, and said its latest letter was triggered by a call for comments by the SEC ahead of staff discussions on the process of proxy votes.