West End Partners, LLC of New York City has purchased 50% of a 220,000 s/f office building at 1351 Washington Blvd. from Diamond Properties of Mt. Kisco, N.Y. for a valuation based on $50 million.
An older office building which was renovated in 2006, the property was 90% occupied at closing. Stamford Hospital is one of the largest tenants.
Matthew Keefe, president of HK Group, the Westport-based commercial Realtor, was the sole broker.

In another transaction, the 54,000 s/f office building at 1290 East Main St. has been sold to Chilton Investment Company from New York City for $11.5 million.
Built in 1989, the building was 60% occupied at closing. Leading tenants include Bartlett Tree and Norseland, Inc.
Keefe was the sole agent involved in this transaction, representing both the buyer and the seller, GHP Office Realty.