UPDATE 1-Ryder cuts forecast on weak rental demand

* Cites weakness in rental demand

* To reduce fleet, implement cost-saving actions

* Shares fall 9 pct

June 21 (Reuters) - Logistics company Ryder Systems Inc cut its quarterly earnings forecast, citing lower demand for its commercial rental services.

The company also plans to cut costs and reduce its commercial rental fleet as it expects the weakness to continue through the year.

Used vehicle inventory will be high for the remainder of the year, Ryder said in a statement.

"Although commercial rental revenue has improved both year-over-year and seasonally, May results reflected lower rental growth than previously discussed," Ryder said in a statement, blaming weak demand and pricing.

Ryder forecast second-quarter earnings of 90 cents to 95 cents per share, down from its earlier view of $1.07 to $1.12 per share.

Higher medical benefit costs are also expected to hurt earnings.

The company expects to incur restructuring charges of 10 cents per share in the quarter, but did not say if that was included in the outlook.

Commercial rental services is part of Ryder's fleet management segment, which accounted for almost 64 percent of the company's total revenue in 2011.

Ryder's rental fleet had about 28,700 trucks and trailers as of Dec. 31, 2011, according to a regulatory filing.

Others segments are performing in line with expectations, Ryder said.

Its shares fell 9 percent to $37 in after-market trading from its Thursday close of $40.75.