Two of the Southland’s largest players in the finished metal and aluminum business announced a $105 million agreement Tuesday to supply heavy and light gauge plate, sheet and coil products to Boeing.

Under the deal, Foothill Ranch-based Kaiser Aluminum Corp. received a three-year contract from a Reliance Steel & Aluminum Co. subsidiary to provide heavy- and light-gauge plate, sheet and coil products to Boeing’s Integrated Defense Systems. Boeing’s IDS units which are spread through Orange and L.A. Counties, include facilities that produce parts for the F-15 Strike Eagle, the F/A-18 Hornet and the C-17 Globemaster III.

Kaiser also said that this deal is part of a $105 million expansion of its Trentwood, Wash., aluminum plant, which will facilitate the new supply agreement. Financial terms were not disclosed.

Shares in Reliance were up 76 cents to $30.57 while shares of Kaiser were up 30 cents to $58 in early trading on Tuesday.