This is a tonneau- shaped 1980s Girard-Perregaux dress watch. The movement is a Peseux 7040. Though this particular watch doesn’t have seconds it’s also available with sub seconds.
This caliber is often used in smaller flat dress watches because it’s a graceful and sleek movement. It’s beautifully finished in comparison to similar movements in other watches. Look at the Geneva stripes and the gold-coloured engravings on the wheel-train bridge.
The watch had a low amplitude and a short power reserve. It also suddenly stopped several times.