The Reagan administration may have gone too far in trying to push the commercialization of federal land-sensing satellites, inadvertently endangering American commercial Landsat ventures.

The French-led competitors for the Landsat market may end up having, for a time, the only land-sensing satellite in orbit.

The administration is now backpedaling at high speed. But it is probably too late to prevent the Europeans from gaining a major advantage, Commerce Department officials say.

Gilbert Weill, president of Spot Image Corp., the American subsidiary of the French-led company, said that the situation "might be a very significant advantage" for his firm.

John McElroy, assistant administrator for satellites of the National Oceanic and Atmospheric Administration, explained the situation to NOAA's Landsat Advisory Committee two weeks ago.

The Landsat trouble began when administration budget-cutters decided that a good way to force private companies into the land-sensing satellite business would be to kill the government's program. The administration wanted to spin off the land-sensing satellites to private firms.

But the transfer was going slowly, so the administration decided to launch no more Landsats after the next one, to help push commercial vendors into the business.

The Landsat now in orbit has broken down. The next to be launched, the fifth in the series, may be put up next spring, with an expected working life of about three years. Thus, by 1987, unless private companies launch their own satellites, there will be no American land-sensing satellites in orbit.

Spot Image plans to launch a satellite in 1985. According to NOAA officials, that may give the French a chance to grab up whatever customers there are for such things as mineral and crop data. The customers then will buy equipment designed to use Spot Image data and incompatible with data from American Landsats.

NOAA officials say that some large firms, such as the oil companies, undoubtedly will buy the services of both American and European satellites. But they contend that smaller customers will have to choose and may pick the Europeans.

Some Reagan administration officials now hope to get the government to commit itself to a sixth and seventh Landsat to provide uninterrupted data from the U.S. government while American entrepreneurs ready their own satellites.

Commerce Secretary Malcolm Baldrige and the Cabinet Council on Commerce and Trade, officials said, had three options.

First, the government simply could go ahead with its plans to sell off the land and weather satellites. The schedule would not permit companies to buy the satellite system before late 1984 at the earliest, then they would have to build and launch a new satellite. By one conservative estimate, it would not be in orbit until 1988.

Another option Baldrige had was to go back to the Carter administration's policy and build the sixth and seventh satellites while commercialization continues. NOAA estimates that it would take up to 5 1/2 years to put up a satellite, so a sixth satellite probably couldn't be launched until at least 1989.

In the end, the council picked a compromise in which the government would preserve its option of building a sixth satellite by buying only the "long lead-time parts" for one. Then, in six months or a year, the administration could decide whether to go ahead with the satellite.

This compromise, which would cost about $15 million, is expected to be recommended to President Reagan.

But, NOAA officials warn, if the decision on this or other options is not made soon and incorporated into the fiscal 1985 budget, the time in which there will be no American Landsat in orbit will lengthen rapidly.