Nov 4 (Reuters) - Adani Enterprises (ADEL.NS), opens new tab reported a drop in second-quarter adjusted profit on Tuesday as weakness in its core coal trading business offset gains in renewable energy, even as its board approved a 250 billion rupee ($2.8 billion) rights issue.

Profit before exceptional items and tax at the flagship firm of India's Adani Group dropped to 8.14 billion rupees ($92.6 million) for the quarter ended Sept. 30, from 24.09 billion rupees a year earlier.

The company recorded an exceptional gain of 35.83 billion rupees in the quarter related to the sale of stake in AWL Agri Business, formerly known as Adani Wilmar.

Coal-fired power generation, which typically contributes to about three-quarters of the country's annual electricity output, has been declining due to the rapid growth of the renewables sector, reflecting a shift in fuel use patterns as the country moves to greener forms of energy.

The ports-to-power conglomerate's coal trading business is its biggest segment, contributing a major portion of its overall revenue.

It reported a near 29% fall in revenue to 66.58 billion rupees in the reporting quarter, lagging behind others in the past six quarters.

The decline outweighed the growth in Adani Enterproses' new energy segment and airport segment, which recorded 3.7% and 42.7% rise in revenue in the quarter.

The new energy segment includes solar manufacturing and wind turbine businesses.

Adani Enterprises' consolidated revenue from operations fell 6% to 212.49 billion rupees.

Shares of the company dropped as much as 3.1% after results and closed 1.9% lower.

($1 = 87.8950 Indian rupees)