UPDATE 2-Swatch Group appoints Nayla Hayek chairwoman

* Nayla Hayek will succeed her father who died on Monday

* Company avoids a double mandate for Nick Hayek

* Shares fall 0.6 percent, in line with the sector index

(Adds analyst comment, updates share price)

By Silke Koltrowitz

ZURICH, June 30 (Reuters) - Swatch Group (UHR.VX), the world's largest watchmaker, appointed Nayla Hayek chairwoman on Wednesday, lifting uncertainty about who would succeed the company's late founder.

Nicolas Hayek, aged 82, died of heart failure on Monday and some analysts expected his son Nick, chief executive of the group since 2003, to take over as head of the board. [ID:nLDE65S0J8]

"With this step Swatch Group does not have the problem of a double mandate for Nick Hayek, but we clearly believe that Nick will be the driving force in the company," Vontobel analyst Rene Weber said.

Swatch Group said in a statement that Nayla Hayek, the CEO's sister, had been groomed for this role. She has been been on the board since 1995 and became vice chairwoman this year.

"This is probably not such a surprise as Nayla was already vice chairman. However, I think Nick Hayek will be in control and see no change in strategy," Kepler Capital Market's analyst Jon Cox said.

Shares in the company were down 0.23 percent at 306.50 Swiss francs at 1417T, in line with the STOXX European sector index .SXQP.

(Additional reporting by Katie Reid; Editing by David Cowell)