COPENHAGEN, June 11 (Reuters) - Some Nordic retail brokerages are allowing clients to vote at Tesla's annual general meeting (AGM) this week, departing from their regular practice, after significant interest from investors and online comments from CEO Elon Musk.

The June 13 AGM is shaping up as a referendum on Musk's leadership, after a judge invalidated the CEO's $56 billion pay package in January, calling it an unfathomable sum.

As major shareholders appear divided over whether to endorse the package, Tesla is seeking support from retail investors who, excluding Musk and his brother, make up 48% of the ownership, an unusually high percentage, according to Bernstein.

Musk will need overwhelming support from retail investors since many institutional counterparts have opted to vote against his pay, a Bernstein note showed.

Musk in May said on social media platform X he would contact banks and brokers that did not allow investors to cast ballots, saying shareholders had the right to vote.

Swedish banking platforms and retail brokerages Avanza and Nordnet both said they had decided to let investors vote after customers requested to do so.

The two brokers, who together count nearly 150,000 Tesla shareholders among their clients, do not normally provide the option to retail customers to vote at non-European AGMs.

"Elon Musk has made it clear that it is important for him that the shareholders of Tesla make their voice heard on this year's AGM," said a Nordnet spokesperson.

"I think it is fair to say that his position has had an indirect effect on us."

Avanza said its decision was based on requests from its customers and the fact that Tesla was one of the most owned stocks on its platform.

Sweden's Swedbank as a part of its regular services registers clients' votes or helps facilitate their digital attendance at AGMs of non-European companies for a fee of 1,000 crowns ($95.23), a spokesperson said.

Nordic banks DNB, Nordea, Danske Bank and SEB did not immediately respond to requests for comment.

($1 = 10.5011 Swedish crowns) (Reporting by Louise Breusch Rasmussen in Copenhagen, editing by Terje Solsvik, Kirsten Donovan)