PARIS — Turkey’s Turksat satellite fleet operator has received best-and-final offers from bidders vying to manufacture the Turksat 4A and Turksat 4B telecommunications satellites in a competition that does not include the company that has built most of the previous Turksat spacecraft, according to industry officials.

Thales Alenia Space is sitting out this contest for reasons that remain unclear.

Turksat is already behind its stated schedule of announcing a winner in time to have the satellites in orbit in 2012, but it has received bids from Mitsubishi Electric Corp. (Melco) of Japan, Lockheed Martin Space Systems of the United States and a team proposing a satellite platform built by Orbital Sciences of the United States with a payload built by Astrium of Europe, officials said.

Dulles, Va.-based Orbital Sciences has partnered before with Thales Alenia Space in addition to bidding on its own for full telecommunications satellites. Officials said a win here would be a first for an Orbital-Astrium team.

Astrium has a joint venture with the Indian Space Research Organisation to provide small telecommunications satellites designed to compete head-on with Orbital, but that product offer has not gained much traction in the market.

Officials from Lockheed Martin and Melco in recent months have said they expected to raise their profile in the commercial satellite market.

In one or another of its corporate incarnations, Thales Alenia Space of France and Italy has built most previous Turksat satellites and was a shareholder in a Turkish startup satellite operator, called Eurasiasat, which has since been folded into Turksat.

A Thales Alenia Space official said the company has elected to focus its attention in Turkey on the Gokturk Earth observation satellite project, a contract won by satellite services provider Telespazio of Rome, which has the same shareholders as Thales Alenia Space.

One industry official said Turksat may have decided to bypass Thales Alenia Space to demonstrate to other builders that it is not wedded to one or another satellite manufacturer.

Turkish government officials in the past have threatened to punish French industry for moves in the French parliament to classify as “genocide” the massacre of Armenians by the Ottoman Empire at the outset of the First World War.

Industry officials have long said that Turkish competitions like this are among the toughest and most exhausting in the world for bidders.

Peter B. de Selding was the Paris bureau chief for SpaceNews.