Two of Caterpillar's five group presidents retiring

Two of Caterpillar Inc's five group presidents are retiring, a loss of key talent as the world's largest maker of tractors, excavators and other heavy equipment tries to navigate the rough global economy.

Rich Lavin, 60, who had overseen Caterpillar's construction industries unit, will be replaced by CFO Ed Rapp, 55, in January, Caterpillar said on Thursday afternoon.

The construction industries unit brought in roughly 34 percent of Caterpillar's 2011 revenue.

Gerard Vittecoq, 64, who had overseen the division selling power generators, will be replaced by Jim Umpleby, an executive who has ran Caterpillar's solar turbine business.

The power systems unit brought in roughly 37 percent of Caterpillar's 2011 revenue.

Rapp will be replaced as CFO by Brad Halverson, 52, who has been running the company's finance services unit.

Peoria, Illinois-based Caterpillar cut its 2015 earnings target last month, citing slowing demand for many of its products amid rising supply costs.

(Corrects ages of some executives)

(Reporting By Ernest Scheyder; Editing by M.D. Golan)