NEW YORK, Oct 17 (Reuters) - Six Flags Entertainment ( FUN )

is adding an executive from activist hedge fund Sachem

Head Capital Management to its board at a time the theme park

operator is facing pressure from several investors to perform

better.

The company said on Friday that it appointed Sachem Head

partner Jonathan Brudnick to the board, expanding the board size

by one to 13. At the end of the year, when two directors retire,

the board will have 11 members. He will also join the nominating

and corporate governance committee.

Six Flags, which has a market capitalization of roughly $2.1

billion, saw its shares lose half of their value this year when

rainy weather at the start of the summer kept visitors away from

its parks. The stock price closed at $21.26 on Thursday and has

lost 55.5% since January.

Sachem Head owns nearly 10% of the company and began

establishing its position in the second quarter. The sagging

share price has also attracted other investors who have been

pushing the company to make changes to lift its stock price.

Last month activist investor Land & Buildings, which owns a

2% stake in the company, again urged the company to spin out its

real estate into a real estate investment trust that its fund

manager, Jonathan Litt, thinks could trade at higher multiples.

The hedge fund first floated the idea of selling off the real

estate in late 2022.

Six Flags Entertainment ( FUN ) was created last year when Six Flags

merged with Cedar Fair.

For Sachem Head this is the second board seat the firm has

scored in the last four weeks after Performance Food Group ( PFGC )

invited Sachem Head founder Scott Ferguson onto its

board shortly after the firm had said it wanted four seats,

including one for Ferguson.