AMSTERDAM (Reuters) - Computer chip equipment maker ASML said it does not expect new U.S. restrictions on semiconductor exports to China, announced on Monday, to hit long-term demand for its products but it is studying the immediate potential impact.

The new U.S. rules are Washington's third crackdown in three years on China's semiconductor industry, tightening regulations on equipment makers and curbing exports to 140 Chinese companies, including additional subsidiaries of China's biggest bespoke chipmaker SMIC.

The latest rules include tighter restrictions on software relevant for ASML, which said it was assessing the potential implications.

"Long term, our scenarios for demand in the semiconductor industry are not expected to be impacted by the new regulations, as (our) scenarios are based on the global demand for wafers rather than on any specific geographic split," the company said in a statement.

ASML shares were down 0.3% at 656.40 euros at 1435GMT.

The new U.S. rules include restrictions on 'computational lithography' - software used to optimize the effectiveness of lithography machines such as those made by ASML and Japanese competitors Nikon and Canon, which use beams of light to help create circuitry.

ASML, the biggest lithography machine maker, says on its website that its computational lithography is also "industry leading" and helps improve chip yield and quality.

The U.S. Commerce Department statement said it aimed to restrict software that could be used to make chips better than thresholds that Washington allows using DUV lithography machines and "multipatterning" - a technique believed to have been employed by SMIC to make advanced smartphone chips for China's Huawei.

"Computational lithography software that is not currently controlled can improve the minimum feature size achievable with DUV to less than 40nm and can facilitate the complex mask decomposition necessary for multipatterning," the Commerce Department said.

"This addition addresses that potential workaround."