UPDATE 2-Platinum Underwriters Q2 profit falls

* Q2 net premiums earned down 10 percent

* Q2 net investment income falls 6 pct

* Q2 net income $98.1 mln vs $99.8 mln yr ago (Adds analyst comment, details)

By Archana Shanker and Supantha Mukherjee

BANGALORE, July 21 (Reuters) - Platinum Underwriters Holdings Ltd (PTP.N) posted a lower second-quarter profit, hurt by a fall in premiums at its casualty, property and marine segments, but the results topped market estimates.

For the quarter, the Bermuda-based property and casualty reinsurer earned $98.1 million or $1.90 a share, compared with $99.8 million, or $1.82 a share, a year earlier.

Analysts were looking for a profit of $1.34 a share, excluding investment losses and gains, according to Reuters Estimates.

Net premiums earned fell 10 percent to $232.5 million, while net investment income fell about 6 percent to $44.1 million.

"So far this year, we have found more attractive underwriting conditions for property and marine than for casualty. However, we may be approaching the bottom of the casualty reinsurance market," Chief Executive Michael Price said in a statement.