* Higher debt servicing, tech costs weigh on 2023 earnings

* Up to 6 bln euros to be returned to shareholders in 2024

* New targets underpinned by organic growth, automation

PARIS, Feb 22 (Reuters) - France's AXA, Europe's second-biggest insurer, pledged on Thursday to deliver higher earnings and returns to shareholders by 2026 by growing its client base, automating processes and reducing labour costs.

The new three-year plan, dubbed "Unlock the Future" -- Thomas Buberl's third since becoming CEO in 2016 -- aims to build on the group's efforts in recent years, marked by assets sales and the turnaround of XL Group, bought for $15.3 billion in 2018.

The insurance sector is navigating in an uncertain economic environment, marked by geopolitical upheavals, higher interest rates and the prospect of climate change driven extreme weather events, which represent both risks and opportunities for international underwriters.

AXA, which posted lower-than-expected annual earnings on Thursday, announced a 2026 average underlying annual earnings growth target of 6-8%, up from 3-7% in its previous plan.

It expects an underlying return on equity of 14-16% over the 2024-26 period, up from 13-15% in its three-year plan that ended in 2023.

AXA said the performance would be underpinned by the addition of new customers across its business lines, including in property and casualty policies dedicated to small and medium-sized companies in Britain, Spain, Italy and the U.S.

It will also improve its productivity by investing in automation and increasing the proportion of staff based in countries where labour costs are lower (India, Morocco & Poland), from 10% to 12%.

The group pledged to return up to 75% of its earnings to shareholders in cash, including a dividend payout ratio of 60%. The new policy translates into a yearly dividend for 2023 of 1.98 euros per share, up 16% from 2022.

Its previous plan offered a dividend only in a range of 55-65%.

In total, AXA will return up to 6 billion euros to shareholders in 2024 via 4.4 billion euros in dividends and up to 1.6 billion euros in share buybacks.

For 2023 AXA posted a 5% rise in underlying earnings to 7.6 billion euros ($8.22 billion), in line with its guidance but slightly below the 7.69 billion expected by analysts in a consensus it compiled.

The company last year posted higher revenue but also faced higher costs for debt servicing and investment in technology.

Gross premiums and other revenue rose 1% to 102.7 billion euros, below the 103 billion expected by analysts, hurt by the loss of two global clients in France and lower sales at its asset management arm.

($1 = 0.9249 euros)

(Reporting by Mathieu Rosemain; editing by Tommy Reggiori Wilkes and Jason Neely)