An investor opposed National Intergroup’s merger.

Batterymarch Financial Management, Boston-based manager of about 5.2% of National Intergroup’s shares, said National’s proposed merger with Los Angeles-based Bergen Brunswig isn’t in shareholders’ best interests. A second big National shareholder, Leucadia National Corp., is waging a proxy fight against the linkup between Bergen, a pharmaceutical distributor, and Pittsburgh-based National, formerly National Steel Corp. National shareholders are to vote on the merger March 7, three days after Bergen shareholders. Known opponents represent about 21% of National’s outstanding shares.