The Genlyte Thomas Group LLC is planning a major expansion into the fast-growing linear lighting market with the proposed purchase of Ledalite Architectural Products Inc., Vancouver. Financial details of the transaction were not disclosed.

Ledalite, with projected 1999 sales of $40 million Canadian, designs and manufactures lighting for offices, schools, universities, transportation facilities and other commercial/institutional buildings.

The acquisition would broaden Genlyte's coverage of the linear lighting market because Ledalite has additional strength in transportation lighting and the energy technologies market-two areas the Genlyte Thomas Group has not been active before. The acquisition is expected to be completed before August 1.