The FTSE 100 closed up by 14 points or nearly 0.2% at 7,248.10.
HSBC reported a 19% fall in first-quarter profits, but the drop was not as big as expected, and its shares ended 2.8% higher.
Fashion retailer Next saw the biggest decline, finishing 5.1% lower after it reported falling sales.
Shares in IAG had gained 2.97% by the end of trading, while TUI had risen by 2.92.%.
Shares in Shell were up nearly 0.5% after it reported a sharp rise in first-quarter profits, helped by higher oil prices.
Elsewhere though falling commodity prices hit shares in mining companies.
On the FTSE 250 copper miner KAZ Minerals ended as the worst performer, down 10%. Vedanta Resources dropped by 6.9%, and gold miner Hochschild Mining lost 3.8%.
The UK's fourth-largest supermarket chain, Morrisons, reported another quarter of healthy sales growth, but after a bright start to trading the shares fell back and finished 1.9% lower.
But the worst performing shares in the FTSE 100 were those of fashion retailer Next.
Rival Marks and Spencer also saw its shares shed 2.5%.
On the FTSE 250, shares in Ladbrokes Coral were down by 4.3% at the close after it reported a 2% drop in UK net revenues at its betting shops.
The bookmaker said tougher trading on the High Street had led to a 7% fall in bets made over the counter, although this had been offset to some extent by an increase in revenues from machines in its shops.
Revenues from online betting jumped 22%, helping total group revenue to rise 5%.
On the currency markets, the pound rose 0.4% against the dollar at $1.2921, but fell 0.4% against the euro to 1.1774 euros.
The price of a barrel of the benchmark Brent Crude oil fell to its lowest level since November - it was down 3.8% at $48.85. Brent crude prices tumbled 2.8% to $49.13.
Earlier the Kremlin said no decision had been made on whether Russia would extend oil cuts into the second half of 2017.
London's key share index edged ahead on Thursday, led by BA-owner International Consolidated Airlines Group (IAG), travel firm TUI and HSBC bank.