DETROIT -- An official says plans for a bridge linking Windsor and Detroit are being held up by delays in buying properties in both cities.

Dwight Duncan, interim chair of the Windsor-Detroit Bridge Authority, tells the Detroit Free Press  that about 30 of the roughly 900 parcels needed in the Delray district of Detroit could pose potential problems if owners resist selling.

In Windsor, meanwhile, the newspaper says negotiations are taking longer than originally anticipated with Hydro One, which has facilities and transmission lines in the zone for the bridge.

The delays have held up release of the bridge authority's formal Request for Proposals, the detailed bid document initially expected by the end of 2015.

The Gordie Howe International Bridge is scheduled to open in 2020.