TOKYO, Feb 2 (Reuters) - A New York university-connected research foundation has filed a lawsuit against Japan chip materials maker JSR, court documents show, saying the company has commercialised its technology without permission.

JSR is a top manufacturer of photoresists, which are chemicals used in chipmaking, with its U.S. subsidiary Inpria working on metal oxide resists for use in extreme ultraviolet (EUV) lithography for production of advanced chips.

The Research Foundation for the State University of New York says its researchers made advances in tin oxide metal photoresists and Inpria is commercialising its intellectual property (IP) without permission.

JSR told Reuters it considers the lawsuit to be without merit and internal investigations have not uncovered any improper activities related to Inpria.

"Inpria is a former university spin-out with deep roots in academic research on metal oxides stretching back two decades," JSR said.

JSR agreed last June to be bought by a government-backed fund in a deal that has been met with surprise, with some industry executives questioning the need for such an intervention.

The company expects the tender offer for its shares to begin in late February at the earliest.

The research foundation says it is seeking a preliminary injunction to prevent transfer of challenged patents to Japan Investment Corp (JIC) and that its IP has been valued at $2.4 billion to $4.3 billion. (Reporting by Sam Nussey and Makiko Yamazaki; Editing by Lincoln Feast.)