Rents for the best office buildings in Abu Dhabi fell for the sixth straight quarter as new developments increased the amount of available space, CB Richard Ellis said.

The average rent for prime properties fell 12% to 2,300 dirhams ($626) a sq m in the first quarter from the previous three months, the Los Angeles-based real-estate broker said in a report published today. The vacancy rate increased by about 2%, versus an average of less than 1% in recent years.