** Shares of laboratory operator Labcorp LH.N fall as much as 8.4% to a three-month low of $252.46

** Stock set for its worst day in three years, if losses hold

** Co expects its contract research unit to grow by 5.7% to 7.1% this year, down from its prior range of 6.1% to 7.5%

** Early-stage drug development revenue for 2025 expected to grow low-single digits compared to mid-single digits estimated before, finance chief Julia Wang says

** Co reports Q3 adj. profit of $4.18/shr vs analysts' average estimate of $4.13/shr - LSEG data

** Co's quarterly revenue of $3.56 billion in-line with analysts' average expectation of $3.55 billion

** LH raises lower end of annual profit forecast to $16.15-$16.50/shr from $16.05-$16.50/shr

** Brokerage Leerink Partners says weakness in early development is being overdone in the stock, as the segment is a small contributor to core profit

** Including session's move, stock up 13.6% YTD

(Reporting by Sahil Pandey in Bengaluru)

((Sahil.Pandey@thomsonreuters.com))