BENGALURU (Reuters) - Dr. Lal PathLabs, India's biggest diagnostics firm by revenue, posted a bigger profit for the fourth straight quarter on Thursday, led by the addition of more labs and increased demand for medical tests.

The company's consolidated net profit jumped 49% year-on-year to 845 million rupees ($10.1 million) in the fourth quarter.

Its shares climbed as much as 7.8% after the results before trimming some gains to trade up about 6%. Rival Metropolis Healthcare was up about 2% and Thyrocare Technologies gained about 1%.

Analysts expect Indian diagnostic firms to benefit from geographic expansions and price hikes.

"We're expanding our reach in core markets by strengthening our presence in Tier 3 and Tier 4 towns," Dr. Lal PathLabs Chief Executive Officer-designate Shankha Banerjee said.

The number of samples tested grew 8.5% during the quarter, and was up roughly 10% for the fiscal year.

The company, which operates more than 280 labs in India, said total revenue climbed by 11% to 5.45 billion rupees.

Thyrocare is scheduled to report its fourth-quarter results next week. ($1 = 83.4872 Indian rupees)

(Reporting by Kashish Tandon and Nandan Mandayam in Bengaluru; Editing by Savio D'Souza)