The company said that the existing operation running between Islay and the Scottish mainland was struggling to cope with demand.

Chairman Harold Mills announced the review following a meeting of the company's board in Oban.

Caledonian MacBrayne attaches the highest priorities to improving the lifeline services to Islay

Harold Mills CalMac chairman

Islay is served by a single ferry operating between Kennacraig on the Kintyre peninsula and the two island terminals at Port Askaig and Port Ellen.

CalMac said that the vessel used on the route - the Clansman - is simply not big enough.

A number of options for the future of the service will now be examined.

These will include the separation of freight traffic, similar to the system now operating between Ullapool and Stornoway on Lewis.

CalMac is likely to retain the option of sailing to two different ports on Islay to allow for weather conditions.

Full consultation

However, the location of the mainland terminal may come under review.

Dr Mills said: "There has been a considerable amount of debate over the years about the kind of service to be provided to Islay and the location of the terminals.

"We will now, in full consultation with our partners and customers, commission a study of the options for the route.

CalMac has announced investment plans

"The study will include an economic and environmental appraisal of all the options."

He hoped this review would be completed by the autumn.

And he stressed: "Caledonian MacBrayne attaches the highest priorities to improving the lifeline services to Islay."

Dr Mills also announced that a second linkspan is to be provided at Oban pier to enhance its operations out of the town.

The move is one of the priorities included in a new 10-year investment plan.

New vessels for Rothesay on Bute and new investment on the Gourock to Dunoon route and the Islay services are also earmarked.