By Alexander Marrow

LONDON, May 6 (Reuters) - A group of Magnum MICCT.AS investors has criticised the ice cream maker over its handling of tensions around its Ben & Jerry's brand's social activism and a lack of transparency over its finances, a letter from shareholders seen by Reuters showed.

The investors, who represent some 1.3% of Magnum stock but manage billions of dollars in assets, called on the firm to explain how it would maintain Ben & Jerry's board independence and to provide standalone sales and profit data for the brand.

The pressure underscores how Ben & Jerry's, which has a history of vocal social activism, poses a challenge for The Magnum Ice Cream Company MICCT.AS, which spun off from consumer goods giant Unilever ULVR.L and listed in December.

Ben & Jerry's founders and board repeatedly clashed with former parent Unilever over political and ethical stances. Magnum has since looked to weaken the control of Ben & Jerry's independent board, which has been reduced to just two members. Former directors are challenging Magnum's actions.

CONCERNS OVER BEN & JERRY'S SOCIAL MISSION

In a letter dated May 1, sent to Magnum's board ahead of its May 7 annual general meeting, shareholders led by NorthStar Asset Management expressed concerns over Magnum's management of Ben & Jerry's, saying it risked damaging its business and value.

"They've dismantled the brand's social mission which, for us as investors, is the brand equity," Whitney Nguyen, director of impact research at NorthStar, told Reuters.

Unilever's 2000 acquisition of Ben & Jerry's granted the brand substantial and uncommon freedoms, including an independent board, and preserved the brand's social mission and charitable work. Unilever still has a 19.9% stake in Magnum.

"While we respectfully disagree with the characterisation presented by NorthStar, we are always happy to engage with shareholders and look forward to doing so," Magnum, which also has such brands as Wall's and Cornetto, said in a statement.

"We remain committed to having a Board, led by an Independent Director, to continue its role of helping guide the social mission and brand integrity, alongside the CEO."

Unilever declined to comment.