The Hastor Group was granted an injunction to block Ningbo Jifeng from exercising a convertible bond ahead of Grammer's annual shareholder meeting on May 24, a Grammer spokesman said on Monday.

"We have appealed the injunction," a Grammer spokesman said.

Bosnia's Hastor family, which owns a stake of at least 20 percent stake in Grammer, has criticised Grammer's management and campaigned for seats on the board of directors. Grammer's management have sought to rebuff Hastor's requests.

The rising influence of the Bosnian group has raised some concerns among Grammer's largest customers, German carmakers, after a dispute between the Hastor family and Volkswagen escalated, resulting in stoppages of VW's Golf assembly line.

Volkswagen accounts for 35 percent of sales at Grammer's automotive business.

Grammer management had hoped to bring Ningbo Jifeng on board as a "white knight."

In February Ningbo subscribed to a 60 million euro mandatory convertible bond representing approximately 9.2 percent of Grammer's share capital.

The Hastor family's investment vehicle, Cascade International Investment GmbH, holds about half the Hastors' stake in Grammer.

The other half is owned by Halog, another investment vehicle. Both are controlled by Damir and Kenan Hastor, who are listed by Forbes as the richest Bosnians.

(Reporting by Alexander Huebner and Edward Taylor, editing by Louise Heavens)