By Helen Reid

LONDON (Reuters) - Britain's leading stock index climbed at the end of a heavy earnings week as strong results from British Airways owner IAG sent the stock flying, while HSBC joined French banking peers in reporting weaker profits and suffering share price falls.

Strong earnings from IAG and Pearson , along with rising commodities stocks, buoyed Britain's FTSE 100 (FTSE) up 0.4 percent, while financials were a drag as heavyweight HSBC fell 3.3 percent.

The index has risen sharply in recent weeks, though it is still underperforming European peers. It's up 9.7 percent since it hit 15-month lows at the end of March, and was on track for its sixth straight week of gains.

British Airways owner IAG (L:ICAG) led the FTSE, up 5.1 percent and near a four-month high after reporting a 75 percent jump in quarterly profit.

The airline did not comment on the group's potential takeover of low-cost competitor Norwegian Air (OL:NWC).

This led the Norwegian airline to slump more than 10 percent. IAG wrote in an investor presentation that it had had contact with the Norwegian board regarding a possible offer, without reaching an agreement.

IAG peer easyJet (L:EZJ) also rose 1.9 percent, among the top FTSE 100 gainers, with Wizz Air (L:WIZZ) up 3.3 percent on the mid-cap index (FTMC).

HSBC (L:HSBA) was the standout faller on the FTSE, down 2.5 percent after results disappointed investors with an unexpected 4 percent drop in first-quarter pre-tax profit.

A share buyback was not sufficient to cheer investors.

"The share buyback of $2 billion is earlier, but also lower than expected," said Charlie Huggins, manager of an income fund at Hargreaves Lansdown (LON:HRGV).

"An improvement in returns well beyond our own and consensus expectations is required to justify the current share price," said Shore Capital analysts.

Shares in education publishing company Pearson (L:PSON) rose 4.6 percent after the firm said it was on track to return to profit growth this year.

The stock rose to its highest since September 2016 on the latest sign the company's turnaround was on track.

"While the full year guidance has been reiterated, we highlight that Q1 is not representative for Pearson and the group's profits are largely weighted towards the second half," said Liberum analysts, who have a "sell" rating on the stock.

Oil majors BP (LON:BP) and Royal Dutch Shell (LON:RDSa) cemented the FTSE's gains as oil prices held near recent highs on tight supplies and tensions over possible new U.S. sanctions against Iran.

Dixons Carphone (L:DC) shares jumped 6.1 percent to the top of the FTSE 250 (FTMC) after RBC analysts increased their estimates and price target on the stock.

"We think electricals trends are robust helped by strong sales of TVs and connected home devices, while the mobile sector remains tough but is no worse," they wrote in a note.