NEW YORK — Although Internet domain names may be getting longer or more complex as websites creatively squeeze into the crowded “.com” address space, most single-letter names like “a.com” and “b.com” remain unused.

That may soon change but the transition won’t be easy — and it could lead to six-figure sales of this new online real estate.

“Obviously this is a valuable commodity,” said Kurt Pritz, ICANN’s vice-president for business operations. “How would the name be sold?”

Names are normally released on a first-come, first-served basis for $10 US or less, a policy that favours those who have written programs to automatically and frequently check for a name’s availability. Auctioning names to the highest bidder is one possibility.

Single-letter names under “.com,” “.net” and “.org” were set aside in 1993 as engineers grew concerned about their ability to meet the expected explosion in demand for domain names. They weren’t sure then whether a single database of names could hold millions — more than 40 million in the case of “.com” today.

Six single-letter names already claimed at the time — “q.com,” “x.com, “z.com,” “i.net,” “q.net,” and “x.org” — were allowed to keep their names for the time being.

A handful of companies have asked ICANN to free up the single characters. Overstock.com Inc., for instance, prefers a single-letter brand of “o.com” because its newer businesses no longer fit its original mission of providing discounts on excess inventory.

The ICANN board must now decide whether and how to release the names.

Matt Bentley, chief executive of domain name broker Sedo.com LLC, said single-letter “.com” names could fetch six-figure sums, and a few might even command more than $1 million from some of the Internet’s biggest companies.