FILE PHOTO: The AIG logo is seen at its building in New York's financial district March 19, 2015. REUTERS/Brendan McDermid

(Reuters) - American International Group Inc AIG.N said on Monday it expected to book pre-tax catastrophe losses of about $3 billion in the third quarter mainly related to hurricanes Harvey, Irma and Maria.

AIG’s shares were down about 1.7 percent at $60.75 in extended trading.

The company estimated pre-tax losses of about $1 billion each from Harvey and Irma, up to $700 million from Maria and additional catastrophe losses, including earthquakes in Mexico, of about $150 million.

Morgan Stanley analysts said the losses were slightly above their estimate of $2.5 billion, but were manageable as it equated to about 2.6 percent of book value.

The analysts, who have an “overweight” rating on the stock, also highlighted the company’s more than $3.5 billion in cash and short-term investments, saying it should help tackle capital concerns from losses in the third quarter.

Insurers and reinsurers are counting the costs of the hurricanes that tore into parts of the United States, while ravaging several islands in the northern Caribbean.

Chubb Ltd CB.N, the world's largest listed property and casualty insurer, has estimated after-tax losses of up to $1.28 billion from hurricanes Harvey and Irma.

Germany's Munich Re MUVGn.DE warned it could miss its profit target this year, the first major reinsurer to flag a hit to earnings from damage caused by the storms.

Hurricane season in the Atlantic is still in full swing and Morgan Stanley said it expects overall insured losses from this year’s catastrophes to approach $100 billion.