For the third time in less than three years, a major laboratory has been charged by Manhattan prosecutors with faking results on its testing of construction materials for monumental building projects — including Yankee Stadium, the Intrepid Museum, the Lincoln Tunnel and the Second Avenue Subway.

Private companies and public authorities had hired American Standard Testing and Consulting Laboratories to test the strength of sample “recipes” of concrete and other building materials, as required by law — but the lab only pretended to do the tests in thousands of instances while pocketing millions in fees over the past decade, officials said yesterday.

In announcing the indictments of lab owner Alan Fortich, 44, and four of the lab’s engineers, officials assured that there are no outstanding safety issues.

That’s because ASTC’s construction-project clients have since conducted new tests and taken remedial action where needed, officials said.