UPDATE 1-Travelers' profit beats on growth in premium across businesses

(Adds details on earnings, share move)

Jan 23 (Reuters) - Property and casualty insurer Travelers Cos Inc reported fourth-quarter profit on Tuesday that beat Wall Street estimates, helped by growth in premiums in all its business segments.

Shares of the Dow-30 company were up 2.6 percent at $143 in premarket trading.

The insurer's net income for the quarter ended Dec. 31 fell 42 percent to $551 million or $1.98 per share and included a charge of $129 million related to the new federal tax law.

On an adjusted basis, the insurer earned $2.28 per share, handily beating the average analyst estimate of $1.51, according to Thomson Reuters I/B/E/S.

The company's net written premiums in the quarter rose 6 percent to $6.42 billion.

Travelers' pre-tax catastrophe losses, net of reinsurance, more than tripled to $499 million from $137 million a year earlier, as a result of the California wildfires.

The figure, however, is lower than the forecast range of $525 million to $675 million.

California's wildfire season in 2017 was the most destructive and deadliest in the state's history, wrecking more than 21,000 homes and 2,800 businesses.

Catastrophe losses in the quarter weighed on the insurer's underwriting gains, which slumped 45 percent to $216 million.

As a result, its combined ratio - a measure of an insurer's profitability - worsened to 95.5 percent from 90 percent a year ago. A ratio below 100 percent indicates the insurer earns more in premiums than it pays out in claims and expenses.

Despite rising interest rates, net investment income fell 5.3 percent to $467 million.

Travelers' revenue rose 3.6 percent to $7.45 billion. (Reporting by Nikhil Subba in Bengaluru; Editing by Arun Koyyur)