July 30 (Reuters) - Allstate ALL.N reported a jump in second-quarter profit on Wednesday, driven by strong underwriting performance and increased investment returns.

Property and casualty insurers benefited during the quarter as individuals and businesses continued spending on insurance policies amid macroeconomic uncertainty and concerns over severe weather-related catastrophes.

Underwriting income in Allstate's property-liability segment jumped to $1.28 billion in the second quarter, up from a loss of $145 million in the year-ago period.

The segment reported an underlying combined ratio of 79.5%, compared to 85.3% a year earlier. A ratio below 100% indicates the insurer earned more in premiums than it paid out in claims.

Insurance bellwether Travelers TRV.N beat Wall Street estimates earlier in the month, while Chubb CB.N also reported higher profits due to effective underwriting and strong portfolio management.

Allstate's net investment income increased to $754 million from $712 million in the same period last year.

The Northbrook, Illinois-based insurer reported adjusted net income of $1.59 billion, or $5.94 per share, for the quarter ended June 30, compared with $429 million, or $1.61 per share, a year earlier.

(Reporting by Pritam Biswas in Bengaluru; Editing by Mohammed Safi Shamsi)

((Pritam.Biswas@thomsonreuters.com;))