The law firms Kirkland & Ellis and Jenner & Block are looking to sublease office space in their new Chicago buildings to smaller law firms or other businesses for temporary periods while the firms grow into their new digs.

Kirkland has signed a letter of intent to sublease one of the 24 floors at its newly constructed office building to the law firm McDonald Hopkins for five years starting in January, said Carl Grassi, the Cleveland-based president of McDonald Hopkins. Kirkland declined to comment. Kirkland last month moved into the building at 300 North LaSalle Street, which was configured to accommodate its 675 Chicago lawyers in one third less space than in its former offices in the Aon and Prudential buildings.

Jenner, a firm with about 450 lawyers mainly in Chicago, is seeking to sublease one of its 14 new floors at 353 North Clark Street, said Donald Resnick, the Jenner partner overseeing the firm’s building construction. The firm had agreed to move onto that floor in three years, but is paying to build it out now and make some money off subleasing it until 2012 if possible, Resnick said. At least one firm has looked at it, he said.

Kirkland and Jenner said they expect to add enough attorneys eventually to make use of the leased floors. Some law firms have cut lawyers and staff to reduce costs amid a slowdown in the legal service business caused by the recession. Jenner earlier this year eliminated 34 support staff positions in its Chicago and Washington offices and said it did not cut lawyers. Kirkland has declined to comment on reports of employee cuts.

McDonald Hopkins, a firm with about 125 lawyers that has roots in Cleveland, already has an office in Chicago, but would be moving a few blocks south from its current location at 640 North LaSalle Street. The firm has 17 lawyers in Chicago now and would like to have about 45 there, Grassi said.

“We’re excited about expanding,” Grassi said. “We’re out of space in our current location and we’re continuing to grow in Chicago.”

Lynne Marek can be reached at [email protected].