* Sika's Burkard family wants to sell to Saint-Gobain
* Sika board, minority shareholders oppose takeover
* Case highlights power of family shareholders in Swiss companies
* Court to rule on board's move to restrict voting rights
By John Revill
ZURICH, Oct 18(Reuters) - One of Europe's most bitter takeover battles is set to enter a key stage soon when a court rules if the founding family of Swiss chemicals maker Sika can sell control to French rival Saint-Gobain.
Investors see the ruling, due by the end of this year, as a test of minority shareholders' rights in Switzerland.
The Sika board and minority shareholders including the Bill & Melinda Gates Foundation Trust oppose the deal, and the case is being watched for how courts treat Sika's Burkard family in a country where family shareholders can often control a listed company with just a fraction of the equity.
The takeover battle began in 2014 when Saint-Gobain offered 2.75 billion Swiss francs ($2.8 bln) to buy Schenker-Winkler Holding (SWH), the Burkards' private vehicle which owns 16 percent of Sika
That would have enabled the French company to take control of Sika for far less than its 11.8 billion franc market value. But the Burkards want to sell and took the case to court after Sika's board restricted the family's voting rights in order to block the bid.
"Saint-Gobain wants only to acquire 16 percent of Sika's capital but take 100 percent of the control over a rival," Sika Chairman Paul Haelg told Reuters.
A court in Sika's home canton of Zug will rule on whether the board has the right to limit the Burkards to 5 percent of the near 53 percent of the voting rights they hold.
"The Sika case and its outcome are catalysts for people to review all their exposure to companies with voting and control distortion," said Iain Richards, head of responsible investment at Columbia Threadneedle Investments, which holds Sika stock worth 300 million Swiss francs.
"If the rules that were established to protect minorities are not worth the paper they are written on, that will affect our view of similar companies," said Richards, who also opposes the sale of Sika, along with Fidelity International, another minority shareholder.
The case highlights investor concerns about the power of family shareholders in some of Switzerland's biggest companies. At drugmaker Roche, for instance, the Hoffmann and Oeri families control 45 percent of shareholder votes with 8.3 percent of the total investment, while watchmaker Swatch is run by the Hayek clan and their allies with roughly 20 percent of the share capital.
Sika's board believes it got the right to restrict the Burkards' voting rights in return for agreeing a stock split in 1993, which gave the family most of the votes despite now having only around 16 percent of the equity.
The Burkards, now in their fourth generation after founding Sika in 1910, insist Sika statutes do not apply to SWH. They say the board acted illegally in restricting the voting power of SWH and want to oust Haelg.
"It's the family's view that they should be allowed to sell the shares with their full rights to whom they want," SWH Chairman Max Roesle told Reuters.
Sika's CEO Jan Jenisch has threatened to quit if the deal goes through.
Lawyers see the final outcome as too close to call, and both sides are likely to appeal against the court's verdict. Saint-Gobain's contract to buy SWH is valid until the end of 2018.
"There have been no cases like this before in Switzerland where the indirect transfer of shares has gone to a court," said Frank Gerhard, a lawyer at Homburger. "We are in uncharted territory."
The outcome could have a big effect on Sika's share price, which plunged 22 percent on the day Saint Gobain's bid emerged as investors believed Sika was better off independent. Analysts expect the shares, which have since recovered following strong financial results, to rise if Sika is successful and decline if the family triumph.
Columbia Threadneedle's Richards said the case was not about family companies and their particular circumstances, but about respecting the rights of all shareholders and existing rules.
"If the shareholder rights and protections are shown to be token and worthless, that will drive discounts in the valuations of companies in similar situations," said Richards.
"Investors become less committed and ultimately the cost of capital can increase," he said. "The case will either show there is a fair and level playing field, or not." ($1 = 0.9768 Swiss francs) (Editing by Susan Fenton)