BEIJING (Bloomberg) - Shareas of China Overseas Land & Investment Ltd. fell by the most in almost two years in Hong Kong after more than 2,800 apartments developed by the company in Shenzhen were blocked from sale by the local land authority.

The shares tumbled as much 7 per cent, the most since March 4, 2013, and traded 5.4 per cent lower at HK$23.90 as of 10:16 a.m. local time. The benchmark Hang Seng Index fell 0.7 per cent. Three calls to the company's Hong Kong-based investor relations department went unanswered. The land authority's website doesn't give a reason for the block.

China Overseas is the latest developer to have projects barred from transactions by authorities in Shenzhen. Kaisa Group Holdings Ltd., which this month missed a coupon payment on a US$500 million bond, also had units blocked from sale.

Shenzhen's land and resources commission said on its official microblog on Friday that authorities block transactions if developers are found to have violated laws or rules. Transactions may also be temporarily blocked for "normal processing," it said.