BERLIN, Aug 25 (Reuters) - German business morale

improved unexpectedly in August to its highest level in 15

months, a survey showed on Monday.

The Ifo institute said its business climate index increased

to 89.0 in August from 88.6 in July, the highest since May of

last year, while analysts polled by Reuters had forecast a

reading of 88.6.

The increase was due to improved expectations among

companies. However, the current situation was assessed as

slightly worse, Ifo said.

"The recovery of the German economy remains weak," Ifo

president Clemens Fuest said.