US Airways has denied recent suspicion that it has begun to block award seats made available by its Star Alliance partners for mileage redemption by members of its Dividend Miles program — a practice pioneered by United Airlines, which I first exposed in 2008.

The airline has been silent on the issue since reports about apparent blocking surfaced last fall. Many travelers said they found award inventory on various Star carriers, using one or more of the publicly available sources — the websites of All Nippon Airways, Continental Airlines and Air Canada — but US Airways agents were unable to see those available seats…