In its biggest gain in more than four years, Commonwealth REIT share prices increased after Related Cos and Keith Meister challenged the plan set by the company of selling shares. The challengers are preparing to make a bid to takeover for US$2.1 billion.

Meister, the founder of Corvex Management LP and Related Cos agree that there is an opportunity to 'meaningfully increase' their offer after the completion of their due diligence review. The valuation made in the offer is at US$25 per share.  Share prices, after the offer was made, increased by 54% to US$24.41.

The two challengers currently own 9.8 percent of existing shares and are opposing a planned stock offering by the REIT company totaling 27 million new shares of stock to raise US$450 million. The proceeds of the stock sale would be used to pay existing debts but it would dilute the current stock ownership, sending share prices tumbling down/